From 4bac15907143de1648f3f1969ed22305e75ae2ee Mon Sep 17 00:00:00 2001 From: Kailun Qin Date: Wed, 1 Sep 2021 13:42:31 -0400 Subject: [PATCH 1/2] libcontainer: add support for Landlock This patch introduces Landlock Linux Security Module (LSM) support in runc, which was landed in Linux kernel 5.13. This allows unprivileged processes to create safe security sandboxes that can securely restrict the ambient rights (e.g. global filesystem access) for themselves. runtime-spec: https://github.com/opencontainers/runtime-spec/pull/1111 Fixes https://github.com/opencontainers/runc/issues/2859 Co-authored-by: Zheao Li Signed-off-by: Kailun Qin Signed-off-by: Manjusaka --- go.mod | 2 + go.sum | 5 ++ libcontainer/configs/config.go | 31 +++++++ libcontainer/landlock/config.go | 35 ++++++++ libcontainer/landlock/landlock.go | 58 +++++++++++++ libcontainer/setns_init_linux.go | 7 ++ libcontainer/specconv/spec_linux.go | 63 ++++++++++++++ libcontainer/specconv/spec_linux_test.go | 103 +++++++++++++++++++++++ libcontainer/standard_init_linux.go | 8 ++ 9 files changed, 312 insertions(+) create mode 100644 libcontainer/landlock/config.go create mode 100644 libcontainer/landlock/landlock.go diff --git a/go.mod b/go.mod index 37d2205e999..df9c1a960ab 100644 --- a/go.mod +++ b/go.mod @@ -33,6 +33,8 @@ require ( require ( github.com/cpuguy83/go-md2man/v2 v2.0.5 // indirect + github.com/landlock-lsm/go-landlock v0.0.0-20210828133255-ec6c6b87a946 github.com/russross/blackfriday/v2 v2.1.0 // indirect github.com/vishvananda/netns v0.0.4 // indirect + kernel.org/pub/linux/libs/security/libcap/psx v1.2.51 // indirect ) diff --git a/go.sum b/go.sum index 0a340f3fb83..e6d8ccf7067 100644 --- a/go.sum +++ b/go.sum @@ -35,6 +35,8 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE= github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk= github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY= github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE= +github.com/landlock-lsm/go-landlock v0.0.0-20210828133255-ec6c6b87a946 h1:RRTOwBnwZR4a3IMyPq1uchxJcrLKWF4NTCHB2fbvo5Y= +github.com/landlock-lsm/go-landlock v0.0.0-20210828133255-ec6c6b87a946/go.mod h1:wjznJ04q4Tvsbx3vkzfmgfEOe6w5dSGlXFa+xbSl9X8= github.com/mdlayher/netlink v1.7.2 h1:/UtM3ofJap7Vl4QWCPDGXY8d3GIY2UGSDbK+QWmY8/g= github.com/mdlayher/netlink v1.7.2/go.mod h1:xraEF7uJbxLhc5fpHL4cPe221LI2bdttWlU+ZGLfQSw= github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U= @@ -86,6 +88,7 @@ golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4= golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o= golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= +golang.org/x/sys v0.0.0-20210823070655-63515b42dcdf/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= @@ -102,3 +105,5 @@ gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ= gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA= gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= +kernel.org/pub/linux/libs/security/libcap/psx v1.2.51 h1:VXVXjnTUsA9zeHIolNb6moSXZavDe1pD8Q0lPXZEOwc= +kernel.org/pub/linux/libs/security/libcap/psx v1.2.51/go.mod h1:+l6Ee2F59XiJ2I6WR5ObpC1utCQJZ/VLsEbQCD8RG24= diff --git a/libcontainer/configs/config.go b/libcontainer/configs/config.go index 22fe0f9b4c1..52f10158411 100644 --- a/libcontainer/configs/config.go +++ b/libcontainer/configs/config.go @@ -10,6 +10,7 @@ import ( "github.com/sirupsen/logrus" "golang.org/x/sys/unix" + "github.com/landlock-lsm/go-landlock/landlock" "github.com/opencontainers/runc/libcontainer/devices" "github.com/opencontainers/runtime-spec/specs-go" ) @@ -85,6 +86,33 @@ type Syscall struct { Args []*Arg `json:"args"` } +// Landlock specifies the Landlock unprivileged access control settings for the container process. +type Landlock struct { + Ruleset *Ruleset `json:"ruleset"` + Rules *Rules `json:"rules"` + DisableBestEffort bool `json:"disableBestEffort"` +} + +// Ruleset identifies a set of rules (i.e., actions on objects) that need to be handled in Landlock. +type Ruleset struct { + HandledAccessFS landlock.AccessFSSet `json:"handledAccessFS"` +} + +// Rules represents the security policies (i.e., actions allowed on objects) in Landlock. +type Rules struct { + PathBeneath []*RulePathBeneath `json:"pathBeneath"` +} + +// RulePathBeneath defines the file-hierarchy typed rule that grants the access rights specified by +// AllowedAccess to the file hierarchies under the given Paths in Landlock. +type RulePathBeneath struct { + AllowedAccess landlock.AccessFSSet `json:"allowedAccess"` + Paths []string `json:"paths"` +} + +// TODO Windows. Many of these fields should be factored out into those parts +// which are common across platforms, and those which are platform specific. + // Config defines configuration options for executing a process inside a contained environment. type Config struct { // NoPivotRoot will use MS_MOVE and a chroot to jail the process into the container's rootfs @@ -225,6 +253,9 @@ type Config struct { // IOPriority is the container's I/O priority. IOPriority *IOPriority `json:"io_priority,omitempty"` + // Landlock specifies the Landlock unprivileged access control settings for the container process. + // NoNewPrivileges must be enabled to use Landlock. + Landlock *Landlock `json:"landlock,omitempty"` } // Scheduler is based on the Linux sched_setattr(2) syscall. diff --git a/libcontainer/landlock/config.go b/libcontainer/landlock/config.go new file mode 100644 index 00000000000..b2b4302b0ec --- /dev/null +++ b/libcontainer/landlock/config.go @@ -0,0 +1,35 @@ +package landlock + +import ( + "fmt" + + "github.com/landlock-lsm/go-landlock/landlock" + ll "github.com/landlock-lsm/go-landlock/landlock/syscall" +) + +var accessFSSets = map[string]landlock.AccessFSSet{ + "execute": ll.AccessFSExecute, + "write_file": ll.AccessFSWriteFile, + "read_file": ll.AccessFSReadFile, + "read_dir": ll.AccessFSReadDir, + "remove_dir": ll.AccessFSRemoveDir, + "remove_file": ll.AccessFSRemoveFile, + "make_char": ll.AccessFSMakeChar, + "make_dir": ll.AccessFSMakeDir, + "make_reg": ll.AccessFSMakeReg, + "make_sock": ll.AccessFSMakeSock, + "make_fifo": ll.AccessFSMakeFifo, + "make_block": ll.AccessFSMakeBlock, + "make_sym": ll.AccessFSMakeSym, +} + +// ConvertStringToAccessFSSet converts a string into a go-landlock AccessFSSet +// access right. +// This gives more explicit control over the mapping between the permitted +// values in the spec and the ones supported in go-landlock library. +func ConvertStringToAccessFSSet(in string) (landlock.AccessFSSet, error) { + if access, ok := accessFSSets[in]; ok { + return access, nil + } + return 0, fmt.Errorf("string %s is not a valid access right for landlock", in) +} diff --git a/libcontainer/landlock/landlock.go b/libcontainer/landlock/landlock.go new file mode 100644 index 00000000000..52b7aa49a02 --- /dev/null +++ b/libcontainer/landlock/landlock.go @@ -0,0 +1,58 @@ +package landlock + +import ( + "errors" + "fmt" + + "github.com/landlock-lsm/go-landlock/landlock" + + "github.com/opencontainers/runc/libcontainer/configs" +) + +// Initialize Landlock unprivileged access control for the container process +// based on the given settings. +// The specified `ruleset` identifies a set of rules (i.e., actions on objects) +// that need to be handled (i.e., restricted) by Landlock. And if no `rule` +// explicitly allow them, they should then be forbidden. +// The `disableBestEffort` input gives control over whether the best-effort +// security approach should be applied for Landlock access rights. +func InitLandlock(config *configs.Landlock) error { + if config == nil { + return errors.New("cannot initialize Landlock - nil config passed") + } + + ruleset := config.Ruleset.HandledAccessFS + llConfig, err := landlock.NewConfig(ruleset) + if err != nil { + return fmt.Errorf("could not create ruleset: %w", err) + } + + if !config.DisableBestEffort { + *llConfig = llConfig.BestEffort() + } + + if err := llConfig.RestrictPaths( + pathAccesses(config.Rules)..., + ); err != nil { + return fmt.Errorf("could not restrict paths: %w", err) + } + + return nil +} + +// Convert Libcontainer RulePathBeneath to go-landlock PathOpt. +func pathAccess(rule *configs.RulePathBeneath) landlock.PathOpt { + return landlock.PathAccess(rule.AllowedAccess, rule.Paths...) +} + +// Convert Libcontainer Rules to an array of go-landlock PathOpt. +func pathAccesses(rules *configs.Rules) []landlock.PathOpt { + pathAccesses := []landlock.PathOpt{} + + for _, rule := range rules.PathBeneath { + opt := pathAccess(rule) + pathAccesses = append(pathAccesses, opt) + } + + return pathAccesses +} diff --git a/libcontainer/setns_init_linux.go b/libcontainer/setns_init_linux.go index 92c6ef77030..713f6c2043c 100644 --- a/libcontainer/setns_init_linux.go +++ b/libcontainer/setns_init_linux.go @@ -12,6 +12,7 @@ import ( "github.com/opencontainers/runc/libcontainer/apparmor" "github.com/opencontainers/runc/libcontainer/keys" + "github.com/opencontainers/runc/libcontainer/landlock" "github.com/opencontainers/runc/libcontainer/seccomp" "github.com/opencontainers/runc/libcontainer/system" "github.com/opencontainers/runc/libcontainer/utils" @@ -116,6 +117,12 @@ func (l *linuxSetnsInit) Init() error { if err != nil { return err } + // `noNewPrivileges` must be enabled to use Landlock. + if l.config.Config.Landlock != nil && l.config.NoNewPrivileges { + if err := landlock.InitLandlock(l.config.Config.Landlock); err != nil { + return fmt.Errorf("unable to init Landlock: %w", err) + } + } // Set seccomp as close to execve as possible, so as few syscalls take // place afterward (reducing the amount of syscalls that users need to // enable in their seccomp profiles). diff --git a/libcontainer/specconv/spec_linux.go b/libcontainer/specconv/spec_linux.go index 79a9a790049..5b24491fff9 100644 --- a/libcontainer/specconv/spec_linux.go +++ b/libcontainer/specconv/spec_linux.go @@ -18,6 +18,7 @@ import ( "github.com/opencontainers/runc/libcontainer/configs" "github.com/opencontainers/runc/libcontainer/devices" "github.com/opencontainers/runc/libcontainer/internal/userns" + "github.com/opencontainers/runc/libcontainer/landlock" "github.com/opencontainers/runc/libcontainer/seccomp" libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils" "github.com/opencontainers/runtime-spec/specs-go" @@ -556,6 +557,19 @@ func CreateLibcontainerConfig(opts *CreateOpts) (*configs.Config, error) { ioPriority := *spec.Process.IOPriority config.IOPriority = &ioPriority } + if spec.Process.Landlock != nil { + landlock, err := SetupLandlock(spec.Process.Landlock) + if err != nil { + return nil, err + } + config.Landlock = landlock + } + + landlock, err := SetupLandlock(spec.Process.Landlock) + if err != nil { + return nil, err + } + config.Landlock = landlock } createHooks(spec, config) config.Version = specs.Version @@ -1135,6 +1149,55 @@ func parseMountOptions(options []string) *configs.Mount { return &m } +func SetupLandlock(ll *specs.Landlock) (*configs.Landlock, error) { + if ll == nil { + return nil, nil + } + + // No ruleset specified, assume landlock disabled. + if ll.Ruleset == nil || len(ll.Ruleset.HandledAccessFS) == 0 { + return nil, nil + } + + newConfig := &configs.Landlock{ + Ruleset: new(configs.Ruleset), + Rules: &configs.Rules{ + PathBeneath: []*configs.RulePathBeneath{}, + }, + DisableBestEffort: ll.DisableBestEffort, + } + + for _, access := range ll.Ruleset.HandledAccessFS { + newAccessFS, err := landlock.ConvertStringToAccessFSSet(string(access)) + if err != nil { + return nil, err + } + newConfig.Ruleset.HandledAccessFS |= newAccessFS + } + + // Loop through all Landlock path beneath rule blocks and convert them to libcontainer format. + for _, rulePath := range ll.Rules.PathBeneath { + if len(rulePath.AllowedAccess) > 0 { + newRule := configs.RulePathBeneath{ + AllowedAccess: 0, + Paths: rulePath.Paths, + } + + for _, access := range rulePath.AllowedAccess { + newAllowedAccess, err := landlock.ConvertStringToAccessFSSet(string(access)) + if err != nil { + return nil, err + } + newRule.AllowedAccess |= newAllowedAccess + } + + newConfig.Rules.PathBeneath = append(newConfig.Rules.PathBeneath, &newRule) + } + } + + return newConfig, nil +} + func SetupSeccomp(config *specs.LinuxSeccomp) (*configs.Seccomp, error) { if config == nil { return nil, nil diff --git a/libcontainer/specconv/spec_linux_test.go b/libcontainer/specconv/spec_linux_test.go index 8c7fb774f97..b5812c0ff5b 100644 --- a/libcontainer/specconv/spec_linux_test.go +++ b/libcontainer/specconv/spec_linux_test.go @@ -2,10 +2,12 @@ package specconv import ( "os" + "reflect" "strings" "testing" dbus "github.com/godbus/dbus/v5" + ll "github.com/landlock-lsm/go-landlock/landlock" "github.com/opencontainers/runc/libcontainer/configs" "github.com/opencontainers/runc/libcontainer/configs/validate" "github.com/opencontainers/runc/libcontainer/devices" @@ -185,6 +187,107 @@ func TestSetupSeccompWrongArchitecture(t *testing.T) { } } +func TestSetupLandlock(t *testing.T) { + conf := &specs.Landlock{ + Ruleset: &specs.LandlockRuleset{ + HandledAccessFS: []specs.LandlockFSAction{ + specs.FSActExecute, + specs.FSActWriteFile, + specs.FSActReadFile, + specs.FSActReadDir, + specs.FSActRemoveDir, + specs.FSActRemoveFile, + specs.FSActMakeChar, + specs.FSActMakeDir, + specs.FSActMakeReg, + specs.FSActMakeSock, + specs.FSActMakeFifo, + specs.FSActMakeBlock, + specs.FSActMakeSym, + }, + }, + Rules: &specs.LandlockRules{ + PathBeneath: []specs.LandlockRulePathBeneath{ + { + AllowedAccess: []specs.LandlockFSAction{ + specs.FSActExecute, + specs.FSActReadFile, + specs.FSActReadDir, + }, + Paths: []string{ + "/usr", + "/bin", + }, + }, + { + AllowedAccess: []specs.LandlockFSAction{ + specs.FSActExecute, + specs.FSActWriteFile, + specs.FSActReadFile, + specs.FSActRemoveFile, + specs.FSActMakeChar, + specs.FSActMakeReg, + specs.FSActMakeSock, + specs.FSActMakeFifo, + specs.FSActMakeBlock, + specs.FSActMakeSym, + }, + Paths: []string{ + "/tmp", + }, + }, + }, + }, + DisableBestEffort: false, + } + + landlock, err := SetupLandlock(conf) + if err != nil { + t.Errorf("Couldn't create Landlock config: %v", err) + } + + // Execute | WriteFile | ReadFile | ReadDir | RemoveDir | RemoveFile | MakeChar | + // MakeDir | MakeReg | MakeSock | MakeFifo | MakeBlock | MakeSym + expectedRulesetAccess := ll.AccessFSSet(0x1FFF) + ruleset := landlock.Ruleset + if ruleset.HandledAccessFS != expectedRulesetAccess { + t.Errorf("Expected ruleset not found, expected %v, got: %v", + expectedRulesetAccess, ruleset.HandledAccessFS) + } + + pathRules := landlock.Rules.PathBeneath + + pathRulesLength := len(pathRules) + if pathRulesLength != 2 { + t.Errorf("Expected 2 path beneath rules, got :%d", pathRulesLength) + } + + expectedPathRulesAccess := []configs.RulePathBeneath{ + { + // Execute | ReadFile | ReadDir + AllowedAccess: 0xD, + Paths: []string{"/usr", "/bin"}, + }, + { + // Execute | WriteFile | ReadFile | RemoveFile | MakeChar | MakeReg | MakeSock | MakeFifo | + // MakeBlock | MakeSym + AllowedAccess: 0x1F67, + Paths: []string{"/tmp"}, + }, + } + + for i, rule := range pathRules { + if !reflect.DeepEqual(*rule, expectedPathRulesAccess[i]) { + t.Errorf("Wrong rule conversion for the rule %d under test, expected %v, got: %v", + i, expectedPathRulesAccess[i], rule) + } + } + + if landlock.DisableBestEffort { + t.Error("Wrong conversion for DisableBestEffort") + } +} + func TestSetupSeccomp(t *testing.T) { errnoRet := uint(55) conf := &specs.LinuxSeccomp{ diff --git a/libcontainer/standard_init_linux.go b/libcontainer/standard_init_linux.go index 9f7fa45d533..b3b8f986424 100644 --- a/libcontainer/standard_init_linux.go +++ b/libcontainer/standard_init_linux.go @@ -14,6 +14,7 @@ import ( "github.com/opencontainers/runc/libcontainer/apparmor" "github.com/opencontainers/runc/libcontainer/configs" "github.com/opencontainers/runc/libcontainer/keys" + "github.com/opencontainers/runc/libcontainer/landlock" "github.com/opencontainers/runc/libcontainer/seccomp" "github.com/opencontainers/runc/libcontainer/system" "github.com/opencontainers/runc/libcontainer/utils" @@ -267,6 +268,13 @@ func (l *linuxStandardInit) Init() error { // https://github.com/torvalds/linux/blob/v4.9/fs/exec.c#L1290-L1318 _ = l.fifoFile.Close() + // NoNewPrivileges must be enabled to use Landlock. + if l.config.Config.Landlock != nil && l.config.NoNewPrivileges { + if err := landlock.InitLandlock(l.config.Config.Landlock); err != nil { + return fmt.Errorf("unable to init Landlock: %w", err) + } + } + s := l.config.SpecState s.Pid = unix.Getpid() s.Status = specs.StateCreated From 85aad48ef4266d8d3d8daf5c2e762bd420a32821 Mon Sep 17 00:00:00 2001 From: Manjusaka Date: Mon, 23 Dec 2024 20:36:51 +0800 Subject: [PATCH 2/2] Vendor dependecy Signed-off-by: Manjusaka --- .../landlock-lsm/go-landlock/LICENSE | 21 + .../go-landlock/landlock/abi_versions.go | 35 + .../go-landlock/landlock/accessfs.go | 68 ++ .../go-landlock/landlock/config.go | 273 ++++++++ .../go-landlock/landlock/landlock.go | 53 ++ .../go-landlock/landlock/restrict.go | 107 +++ .../go-landlock/landlock/syscall/landlock.go | 128 ++++ .../linux/libs/security/libcap/psx/License | 396 +++++++++++ .../pub/linux/libs/security/libcap/psx/README | 28 + .../pub/linux/libs/security/libcap/psx/doc.go | 60 ++ .../pub/linux/libs/security/libcap/psx/psx.c | 644 ++++++++++++++++++ .../pub/linux/libs/security/libcap/psx/psx.go | 19 + .../linux/libs/security/libcap/psx/psx_cgo.go | 79 +++ .../libs/security/libcap/psx/psx_syscall.h | 74 ++ vendor/modules.txt | 7 + 15 files changed, 1992 insertions(+) create mode 100644 vendor/github.com/landlock-lsm/go-landlock/LICENSE create mode 100644 vendor/github.com/landlock-lsm/go-landlock/landlock/abi_versions.go create mode 100644 vendor/github.com/landlock-lsm/go-landlock/landlock/accessfs.go create mode 100644 vendor/github.com/landlock-lsm/go-landlock/landlock/config.go create mode 100644 vendor/github.com/landlock-lsm/go-landlock/landlock/landlock.go create mode 100644 vendor/github.com/landlock-lsm/go-landlock/landlock/restrict.go create mode 100644 vendor/github.com/landlock-lsm/go-landlock/landlock/syscall/landlock.go create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/License create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/README create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/doc.go create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.c create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.go create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_cgo.go create mode 100644 vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_syscall.h diff --git a/vendor/github.com/landlock-lsm/go-landlock/LICENSE b/vendor/github.com/landlock-lsm/go-landlock/LICENSE new file mode 100644 index 00000000000..aaa7810eb0d --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/LICENSE @@ -0,0 +1,21 @@ +MIT License + +Copyright (c) 2021 Günther Noack + +PERMISSION is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/vendor/github.com/landlock-lsm/go-landlock/landlock/abi_versions.go b/vendor/github.com/landlock-lsm/go-landlock/landlock/abi_versions.go new file mode 100644 index 00000000000..f53ad7dc4e7 --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/landlock/abi_versions.go @@ -0,0 +1,35 @@ +package landlock + +import ll "github.com/landlock-lsm/go-landlock/landlock/syscall" + +type abiInfo struct { + version int + supportedAccessFS AccessFSSet +} + +var abiInfos = []abiInfo{ + { + version: 0, + supportedAccessFS: 0, + }, + { + version: 1, + supportedAccessFS: (1 << 13) - 1, + }, +} + +// getSupportedABIVersion returns the kernel-supported ABI version. +// +// If the ABI version supported by the kernel is higher than the +// newest one known to go-landlock, the highest ABI version known to +// go-landlock is returned. +func getSupportedABIVersion() abiInfo { + v, err := ll.LandlockGetABIVersion() + if err != nil { + v = 0 // ABI version 0 is "no Landlock support". + } + if v >= len(abiInfos) { + v = len(abiInfos) - 1 + } + return abiInfos[v] +} diff --git a/vendor/github.com/landlock-lsm/go-landlock/landlock/accessfs.go b/vendor/github.com/landlock-lsm/go-landlock/landlock/accessfs.go new file mode 100644 index 00000000000..41f08022dd3 --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/landlock/accessfs.go @@ -0,0 +1,68 @@ +package landlock + +import ( + "fmt" + "strings" +) + +var flagNames = []string{ + "Execute", + "WriteFile", + "ReadFile", + "ReadDir", + "RemoveDir", + "RemoveFile", + "MakeChar", + "MakeDir", + "MakeReg", + "MakeSock", + "MakeFifo", + "MakeBlock", + "MakeSym", +} + +// AccessFSSet is a set of Landlockable file system access operations. +type AccessFSSet uint64 + +var supportedAccessFS = AccessFSSet((1 << 13) - 1) + +func (a AccessFSSet) String() string { + if a.isEmpty() { + return "∅" + } + var b strings.Builder + b.WriteByte('{') + for i := 0; i < 64; i++ { + if a&(1< 1 { + b.WriteByte(',') + } + if i < len(flagNames) { + b.WriteString(flagNames[i]) + } else { + b.WriteString(fmt.Sprintf("1<<%v", i)) + } + } + b.WriteByte('}') + return b.String() +} + +func (a AccessFSSet) isSubset(b AccessFSSet) bool { + return a&b == a +} + +func (a AccessFSSet) intersect(b AccessFSSet) AccessFSSet { + return a & b +} + +func (a AccessFSSet) isEmpty() bool { + return a == 0 +} + +// valid returns true iff the given AccessFSSet is supported by this +// version of go-landlock. +func (a AccessFSSet) valid() bool { + return a.isSubset(supportedAccessFS) +} diff --git a/vendor/github.com/landlock-lsm/go-landlock/landlock/config.go b/vendor/github.com/landlock-lsm/go-landlock/landlock/config.go new file mode 100644 index 00000000000..af4187de519 --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/landlock/config.go @@ -0,0 +1,273 @@ +package landlock + +import ( + "errors" + "fmt" + + ll "github.com/landlock-lsm/go-landlock/landlock/syscall" +) + +// Access permission sets for filesystem access. +const ( + // The set of access rights that only apply to files. + accessFile AccessFSSet = ll.AccessFSExecute | ll.AccessFSWriteFile | ll.AccessFSReadFile + + // The set of access rights associated with read access to files and directories. + accessFSRead AccessFSSet = ll.AccessFSExecute | ll.AccessFSReadFile | ll.AccessFSReadDir + + // The set of access rights associated with write access to files and directories. + accessFSWrite AccessFSSet = ll.AccessFSWriteFile | ll.AccessFSRemoveDir | ll.AccessFSRemoveFile | ll.AccessFSMakeChar | ll.AccessFSMakeDir | ll.AccessFSMakeReg | ll.AccessFSMakeSock | ll.AccessFSMakeFifo | ll.AccessFSMakeBlock | ll.AccessFSMakeSym + + // The set of access rights associated with read and write access to files and directories. + accessFSReadWrite AccessFSSet = accessFSRead | accessFSWrite +) + +// These are Landlock configurations for the currently supported +// Landlock ABI versions, configured to restrict the highest possible +// set of operations possible for each version. +// +// The higher the ABI version, the more operations Landlock will be +// able to restrict. +var ( + // Landlock V1 support (basic file operations). + V1 = Config{ + handledAccessFS: abiInfos[1].supportedAccessFS, + } +) + +// The Landlock configuration describes the desired set of +// landlockable operations to be restricted and the constraints on it +// (e.g. best effort mode). +type Config struct { + handledAccessFS AccessFSSet + bestEffort bool +} + +// NewConfig creates a new Landlock configuration with the given parameters. +// +// Passing an AccessFSSet will set that as the set of file system +// operations to restrict when enabling Landlock. The AccessFSSet +// needs to stay within the bounds of what go-landlock supports. +func NewConfig(args ...interface{}) (*Config, error) { + // Implementation note: This factory is written with future + // extensibility in mind. Only specific types are supported as + // input, but in the future more might be added. + // + // This constructor ensures that callers can't construct + // invalid Config values. + var c Config + for _, arg := range args { + if afs, ok := arg.(AccessFSSet); ok { + if !c.handledAccessFS.isEmpty() { + return nil, errors.New("only one AccessFSSet may be provided") + } + if !afs.valid() { + return nil, errors.New("unsupported AccessFSSet value; upgrade go-landlock?") + } + c.handledAccessFS = afs + } else { + return nil, fmt.Errorf("unknown argument %v; only AccessFSSet-type argument is supported", arg) + } + } + return &c, nil +} + +// MustConfig is like NewConfig but panics on error. +func MustConfig(args ...interface{}) Config { + c, err := NewConfig(args...) + if err != nil { + panic(err) + } + return *c +} + +// String builds a human-readable representation of the Config. +func (c Config) String() string { + abi := abiInfo{version: -1} // invalid + for _, a := range abiInfos { + if c.handledAccessFS.isSubset(a.supportedAccessFS) { + abi = a + } + } + + var desc = c.handledAccessFS.String() + if abi.supportedAccessFS == c.handledAccessFS { + desc = "all" + } + + var bestEffort = "" + if c.bestEffort { + bestEffort = " (best effort)" + } + + var version string + if abi.version < 0 { + version = "V???" + } else { + version = fmt.Sprintf("V%v", abi.version) + } + + return fmt.Sprintf("{Landlock %v; HandledAccessFS: %v%v}", version, desc, bestEffort) +} + +// BestEffort returns a config that will opportunistically enforce +// the strongest rules it can, up to the given ABI version, working +// with the level of Landlock support available in the running kernel. +// +// Warning: A best-effort call to RestrictPaths() will succeed without +// error even when Landlock is not available at all on the current kernel. +func (c Config) BestEffort() Config { + cfg := c + cfg.bestEffort = true + return cfg +} + +// PathOpt is an option value for RestrictPaths(). +type PathOpt struct { + accessFS AccessFSSet + paths []string +} + +// PathAccess is a RestrictPaths() option that grants the access right +// specified by accessFS to the file hierarchies under the given paths. +// +// When accessFS is larger than what is permitted by the Landlock +// version in use, only the applicable subset of accessFS will be used. +// +// Most users should use the functions RODirs, RWDirs, ROFiles and +// RWFiles instead, which provide canned options for commonly used +// values of accessFS. +// +// Filesystem access rights are represented using bits in a uint64. +// The individual access rights and their meaning are defined in the +// landlock/syscall package and explained further in the kernel +// documentation at +// https://www.kernel.org/doc/html/latest/userspace-api/landlock.html#access-rights +func PathAccess(accessFS AccessFSSet, paths ...string) PathOpt { + return PathOpt{ + accessFS: accessFS, + paths: paths, + } +} + +// RODirs is a RestrictPaths() option that grants common read-only +// access to files and directories and permits executing files. +func RODirs(paths ...string) PathOpt { return PathAccess(accessFSRead, paths...) } + +// RWDirs is a RestrictPaths() option that grants full (read and +// write) access to files and directories under the given paths. +func RWDirs(paths ...string) PathOpt { return PathAccess(accessFSReadWrite, paths...) } + +// ROFiles is a RestrictPaths() option that grants common read access +// to individual files, but not to directories, for the file +// hierarchies under the given paths. +func ROFiles(paths ...string) PathOpt { return PathAccess(accessFSRead&accessFile, paths...) } + +// RWFiles is a RestrictPaths() option that grants common read and +// write access to files under the given paths, but it does not permit +// access to directories. +func RWFiles(paths ...string) PathOpt { return PathAccess(accessFSReadWrite&accessFile, paths...) } + +// RestrictPaths restricts all goroutines to only "see" the files +// provided as inputs. After this call successfully returns, the +// goroutines will only be able to use files in the ways as they were +// specified in advance in the call to RestrictPaths. +// +// Example: The following invocation will restrict all goroutines so +// that it can only read from /usr, /bin and /tmp, and only write to +// /tmp: +// +// err := landlock.V1.RestrictPaths( +// landlock.RODirs("/usr", "/bin"), +// landlock.RWDirs("/tmp"), +// ) +// if err != nil { +// log.Fatalf("landlock.V1.RestrictPaths(): %v", err) +// } +// +// RestrictPaths returns an error if any of the given paths does not +// denote an actual directory or file, or if Landlock can't be enforced +// using the desired ABI version constraints. +// +// RestrictPaths also sets the "no new privileges" flag for all OS +// threads managed by the Go runtime. +// +// Restrictable access rights +// +// The notions of what "reading" and "writing" mean are limited by what +// the selected Landlock version supports. +// +// Calling RestrictPaths() with a given Landlock ABI version will +// inhibit all future calls to the access rights supported by this ABI +// version, unless the accessed path is in a file hierarchy that is +// specifically allow-listed for a specific set of access rights. +// +// The overall set of operations that RestrictPaths can restrict are: +// +// For reading: +// +// • Executing a file (V1+) +// +// • Opening a file with read access (V1+) +// +// • Opening a directory or listing its content (V1+) +// +// +// For writing: +// +// • Opening a file with write access (V1+) +// +// +// For directory manipulation: +// +// • Removing an empty directory or renaming one (V1+) +// +// • Removing (or renaming) a file (V1+) +// +// • Creating (or renaming or linking) a character device (V1+) +// +// • Creating (or renaming) a directory (V1+) +// +// • Creating (or renaming or linking) a regular file (V1+) +// +// • Creating (or renaming or linking) a UNIX domain socket (V1+) +// +// • Creating (or renaming or linking) a named pipe (V1+) +// +// • Creating (or renaming or linking) a block device (V1+) +// +// • Creating (or renaming or linking) a symbolic link (V1+) +// +// Future versions of Landlock will be able to inhibit more operations. +// Quoting the Landlock documentation: +// +// It is currently not possible to restrict some file-related +// actions accessible through these syscall families: chdir(2), +// truncate(2), stat(2), flock(2), chmod(2), chown(2), setxattr(2), +// utime(2), ioctl(2), fcntl(2), access(2). Future Landlock +// evolutions will enable to restrict them. +// +// The access rights are documented in more depth at: +// https://www.kernel.org/doc/html/latest/userspace-api/landlock.html#access-rights +// +// Helper functions for selecting access rights +// +// These helper functions help selecting common subsets of access rights: +// +// • RODirs() selects access rights in the group "for reading". +// In V1, this means reading files, listing directories and executing files. +// +// • RWDirs() selects access rights in the group "for reading", "for writing" and +// "for directory manipulation". In V1, this grants the full set of access rights. +// +// • ROFiles() is like RODirs(), but does not select directory-specific access rights. +// In V1, this means reading and executing files. +// +// • RWFiles() is like RWDirs(), but does not select directory-specific access rights. +// In V1, this means reading, writing and executing files. +// +// The PathAccess() option lets callers define custom subsets of these +// access rights. +func (c Config) RestrictPaths(opts ...PathOpt) error { + return restrictPaths(c, opts...) +} diff --git a/vendor/github.com/landlock-lsm/go-landlock/landlock/landlock.go b/vendor/github.com/landlock-lsm/go-landlock/landlock/landlock.go new file mode 100644 index 00000000000..9dfa7f6e490 --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/landlock/landlock.go @@ -0,0 +1,53 @@ +// Package landlock restricts a Go program's ability to use files. +// +// The following invocation will restrict all goroutines so that they +// can only read from /usr, /bin and /tmp, and only write to /tmp: +// +// err := landlock.V1.BestEffort().RestrictPaths( +// landlock.RODirs("/usr", "/bin"), +// landlock.RWDirs("/tmp"), +// ) +// +// This will restrict file access using Landlock V1, if available. If +// unavailable, it will attempt using earlier Landlock versions than +// the one requested. If no Landlock version is available, it will +// still succeed, without restricting file accesses. +// +// More possible invocations +// +// landlock.V1.RestrictPaths(...) enforces the given rules using the +// capabilities of Landlock V1, but returns an error if that is not +// available. +// +// Landlock ABI versioning +// +// Callers need to identify at which ABI level they want to use +// Landlock and call RestrictPaths on the corresponding ABI constant. +// Currently the only available ABI variant is V1, which restricts +// basic filesystem operations. +// +// When new Landlock versions become available in landlock, users +// will need to upgrade their usages manually to higher Landlock +// versions, as there is a risk that new Landlock versions will break +// operations that their programs rely on. +// +// Graceful degradation on older kernels +// +// Programs that get run on different kernel versions will want to use +// the Config.BestEffort() method to gracefully degrade to using the +// best available Landlock version on the current kernel. +// +// Caveats +// +// This warning only applies to programs using cgo and linking C +// libraries that start OS threads through means other than +// pthread_create() before landlock is called: +// +// When using cgo, the landlock package relies on libpsx in order to +// apply the rules across all OS threads, (rather than just the ones +// managed by the Go runtime). psx achieves this by wrapping the +// C-level phtread_create() API which is very commonly used on Unix to +// start threads. However, C libraries calling clone(2) through other +// means before landlock is called might still create threads that +// won't have Landlock protections. +package landlock diff --git a/vendor/github.com/landlock-lsm/go-landlock/landlock/restrict.go b/vendor/github.com/landlock-lsm/go-landlock/landlock/restrict.go new file mode 100644 index 00000000000..247509a8667 --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/landlock/restrict.go @@ -0,0 +1,107 @@ +package landlock + +import ( + "errors" + "fmt" + "syscall" + + ll "github.com/landlock-lsm/go-landlock/landlock/syscall" + "golang.org/x/sys/unix" +) + +// The actual restrictPaths implementation. +func restrictPaths(c Config, opts ...PathOpt) error { + handledAccessFS := c.handledAccessFS + abi := getSupportedABIVersion() + if c.bestEffort { + handledAccessFS = handledAccessFS.intersect(abi.supportedAccessFS) + } else { + if !handledAccessFS.isSubset(abi.supportedAccessFS) { + return fmt.Errorf("missing kernel Landlock support. Got Landlock ABI v%v, wanted %v", abi.version, c.String()) + } + } + if handledAccessFS.isEmpty() { + return nil // Success: Nothing to restrict. + } + + rulesetAttr := ll.RulesetAttr{ + HandledAccessFS: uint64(handledAccessFS), + } + fd, err := ll.LandlockCreateRuleset(&rulesetAttr, 0) + if err != nil { + if errors.Is(err, syscall.ENOSYS) || errors.Is(err, syscall.EOPNOTSUPP) { + err = errors.New("landlock is not supported by kernel or not enabled at boot time") + } + if errors.Is(err, syscall.EINVAL) { + err = errors.New("unknown flags, unknown access, or too small size") + } + // Bug, because these should have been caught up front with the ABI version check. + return bug(fmt.Errorf("landlock_create_ruleset: %w", err)) + } + defer syscall.Close(fd) + + for _, opt := range opts { + accessFS := opt.accessFS.intersect(handledAccessFS) + if err := populateRuleset(fd, opt.paths, accessFS); err != nil { + return err + } + } + + if err := ll.AllThreadsPrctl(unix.PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); err != nil { + // This prctl invocation should always work. + return bug(fmt.Errorf("prctl(PR_SET_NO_NEW_PRIVS): %v", err)) + } + + if err := ll.AllThreadsLandlockRestrictSelf(fd, 0); err != nil { + if errors.Is(err, syscall.E2BIG) { + // Other errors than E2BIG should never happen. + return fmt.Errorf("the maximum number of stacked rulesets is reached for the current thread: %w", err) + } + return bug(fmt.Errorf("landlock_restrict_self: %w", err)) + } + return nil +} + +func populateRuleset(rulesetFd int, paths []string, access AccessFSSet) error { + for _, p := range paths { + if err := populate(rulesetFd, p, access); err != nil { + return fmt.Errorf("populating ruleset for %q with access %v: %w", p, access, err) + } + } + return nil +} + +func populate(rulesetFd int, path string, access AccessFSSet) error { + fd, err := syscall.Open(path, unix.O_PATH|unix.O_CLOEXEC, 0) + if err != nil { + return fmt.Errorf("open: %w", err) + } + defer syscall.Close(fd) + + pathBeneath := ll.PathBeneathAttr{ + ParentFd: fd, + AllowedAccess: uint64(access), + } + err = ll.LandlockAddPathBeneathRule(rulesetFd, &pathBeneath, 0) + if err != nil { + if errors.Is(err, syscall.EINVAL) { + // The ruleset access permissions must be a superset of the ones we restrict to. + // This should never happen because the call to populate() ensures that. + err = bug(fmt.Errorf("invalid flags, or inconsistent access in the rule: %w", err)) + } else if errors.Is(err, syscall.ENOMSG) && access == 0 { + err = fmt.Errorf("empty access rights: %w", err) + } else { + // Other errors should never happen. + err = bug(err) + } + return fmt.Errorf("landlock_add_rule: %w", err) + } + return nil +} + +// Denotes an error that should not have happened. +// If such an error occurs anyway, please try upgrading the library +// and file a bug to github.com/landlock-lsm/go-landlock if the issue persists. +func bug(err error) error { + return fmt.Errorf("BUG(go-landlock): This should not have happened: %w", err) +} diff --git a/vendor/github.com/landlock-lsm/go-landlock/landlock/syscall/landlock.go b/vendor/github.com/landlock-lsm/go-landlock/landlock/syscall/landlock.go new file mode 100644 index 00000000000..94417e486a7 --- /dev/null +++ b/vendor/github.com/landlock-lsm/go-landlock/landlock/syscall/landlock.go @@ -0,0 +1,128 @@ +// Package syscall provides a low-level interface to the Linux Landlock sandboxing feature. +// +// The package contains constants and syscall wrappers. The syscall +// wrappers whose names start with AllThreads will execute the syscall +// on all OS threads belonging to the current process, as long as +// these threads have been started implicitly by the Go runtime or +// using `pthread_create`. +// +// This package package is a stopgap solution while there is no +// Landlock support in x/sys/unix. The syscall package is considered +// highly unstable and may change or disappear without warning. +// +// The full documentation can be found at +// https://www.kernel.org/doc/html/latest/userspace-api/landlock.html. +package syscall + +import ( + "syscall" + "unsafe" + + "golang.org/x/sys/unix" + "kernel.org/pub/linux/libs/security/libcap/psx" +) + +// Landlock access rights, for use in "access" bit fields. +// +// Please see the full documentation at +// https://www.kernel.org/doc/html/latest/userspace-api/landlock.html#access-rights. +const ( + AccessFSExecute = (1 << 0) + AccessFSWriteFile = (1 << 1) + AccessFSReadFile = (1 << 2) + AccessFSReadDir = (1 << 3) + AccessFSRemoveDir = (1 << 4) + AccessFSRemoveFile = (1 << 5) + AccessFSMakeChar = (1 << 6) + AccessFSMakeDir = (1 << 7) + AccessFSMakeReg = (1 << 8) + AccessFSMakeSock = (1 << 9) + AccessFSMakeFifo = (1 << 10) + AccessFSMakeBlock = (1 << 11) + AccessFSMakeSym = (1 << 12) +) + +// RulesetAttr is the Landlock ruleset definition. +// +// Argument of LandlockCreateRuleset(). This structure can grow in future versions of Landlock. +// +// C version is in usr/include/linux/landlock.h +type RulesetAttr struct { + HandledAccessFS uint64 +} + +// The size of the RulesetAttr struct in bytes. +const rulesetAttrSize = 8 + +// LandlockCreateRuleset creates a ruleset file descriptor with the +// given attributes. +func LandlockCreateRuleset(attr *RulesetAttr, flags int) (fd int, err error) { + r0, _, e1 := syscall.Syscall(unix.SYS_LANDLOCK_CREATE_RULESET, uintptr(unsafe.Pointer(attr)), uintptr(rulesetAttrSize), uintptr(flags)) + fd = int(r0) + if e1 != 0 { + err = syscall.Errno(e1) + } + return +} + +// LandlockGetABIVersion returns the supported Landlock ABI version (starting at 1). +func LandlockGetABIVersion() (version int, err error) { + const LANDLOCK_CREATE_RULESET_VERSION = 1 << 0 + r0, _, e1 := syscall.Syscall(unix.SYS_LANDLOCK_CREATE_RULESET, 0, 0, LANDLOCK_CREATE_RULESET_VERSION) + version = int(r0) + if e1 != 0 { + err = syscall.Errno(e1) + } + return +} + +// There is currently only one Landlock rule type. +const RuleTypePathBeneath = 1 + +// PathBeneathAttr references a file hierarchy and defines the desired +// extent to which it should be usable when the rule is enforced. +type PathBeneathAttr struct { + // AllowedAccess is a bitmask of allowed actions for this file + // hierarchy (cf. "Filesystem flags"). The enabled bits must + // be a subset of the bits defined in the ruleset. + AllowedAccess uint64 + + // ParentFd is a file descriptor, open with `O_PATH`, which identifies + // the parent directory of a file hierarchy, or just a file. + ParentFd int +} + +// LandlockAddPathBeneathRule adds a rule of type "path beneath" to +// the given ruleset fd. attr defines the rule parameters. flags must +// currently be 0. +func LandlockAddPathBeneathRule(rulesetFd int, attr *PathBeneathAttr, flags int) error { + return LandlockAddRule(rulesetFd, RuleTypePathBeneath, unsafe.Pointer(attr), flags) +} + +// LandlockAddRule is the generic landlock_add_rule syscall. +func LandlockAddRule(rulesetFd int, ruleType int, ruleAttr unsafe.Pointer, flags int) (err error) { + _, _, e1 := syscall.Syscall6(unix.SYS_LANDLOCK_ADD_RULE, uintptr(rulesetFd), uintptr(ruleType), uintptr(ruleAttr), uintptr(flags), 0, 0) + if e1 != 0 { + err = syscall.Errno(e1) + } + return +} + +// AllThreadsLandlockRestrictSelf enforces the given ruleset on all OS +// threads belonging to the current process. +func AllThreadsLandlockRestrictSelf(rulesetFd int, flags int) (err error) { + _, _, e1 := psx.Syscall3(unix.SYS_LANDLOCK_RESTRICT_SELF, uintptr(rulesetFd), uintptr(flags), 0) + if e1 != 0 { + err = syscall.Errno(e1) + } + return +} + +// AllThreadsPrctl is like unix.Prctl, but gets applied on all OS threads at the same time. +func AllThreadsPrctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (err error) { + _, _, e1 := psx.Syscall6(syscall.SYS_PRCTL, uintptr(option), uintptr(arg2), uintptr(arg3), uintptr(arg4), uintptr(arg5), 0) + if e1 != 0 { + err = syscall.Errno(e1) + } + return +} diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/License b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/License new file mode 100644 index 00000000000..2645a87d4c7 --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/License @@ -0,0 +1,396 @@ +Unless otherwise *explicitly* stated, the following text describes the +licensed conditions under which the contents of this libcap/psx release +may be used and distributed. + +The licensed conditions are one or the other of these two Licenses: + + - BSD 3-clause + - GPL v2.0 + +------------------------------------------------------------------------- +BSD 3-clause: +------------- + +Redistribution and use in source and binary forms of libcap/psx, with +or without modification, are permitted provided that the following +conditions are met: + +1. Redistributions of source code must retain any existing copyright + notice, and this entire permission notice in its entirety, + including the disclaimer of warranties. + +2. Redistributions in binary form must reproduce all prior and current + copyright notices, this list of conditions, and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + +3. 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It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + + Gnomovision version 69, Copyright (C) year name of author + Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, the commands you use may +be called something other than `show w' and `show c'; they could even be +mouse-clicks or menu items--whatever suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the program + `Gnomovision' (which makes passes at compilers) written by James Hacker. + + , 1 April 1989 + Ty Coon, President of Vice + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/README b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/README new file mode 100644 index 00000000000..e4f90014275 --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/README @@ -0,0 +1,28 @@ +Package "psx" provides an API for invoking system calls in a way that +each system call is mirrored on all OS threads of the combined Go/CGo +runtime. Since the Go runtime treats OS threads as interchangeable, a +feature like this is needed to meaningfully change process privilege +(including dropping privilege) in a Go program running on Linux. This +package is required by: + + "kernel.org/pub/linux/libs/security/libcap/cap" + +When compiled CGO_ENABLED=0, the functionality requires go1.16+ to +build. That release of Go introduced syscall.AllThreadsSyscall*() +APIs. When compiled this way, the "psx" package functions +psx.Syscall3() and psx.Syscall6() are aliased to +syscall.AllThreadsSyscall() and syscall.AllThreadsSyscall6() +respectively. + +When compiled CGO_ENABLED=1, the functionality is implemented by C +code, [lib]psx, which is distributed with libcap. + +The official release announcement site for libcap and libpsx is: + + https://sites.google.com/site/fullycapable/ + +Like libcap/libpsx itself, the "psx" package is distributed with a +"you choose" License. Specifically: BSD three clause, or GPL2. See the +License file. + +Andrew G. Morgan diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/doc.go b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/doc.go new file mode 100644 index 00000000000..384b0d3e5e2 --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/doc.go @@ -0,0 +1,60 @@ +// Package psx provides support for system calls that are run +// simultanously on all threads under Linux. +// +// This property can be used to work around a historical lack of +// native Go support for such a feature. Something that is the subject +// of: +// +// https://github.com/golang/go/issues/1435 +// +// The package works differently depending on whether or not +// CGO_ENABLED is 0 or 1. +// +// In the former case, psx is a low overhead wrapper for the two +// native go calls: syscall.AllThreadsSyscall() and +// syscall.AllThreadsSyscall6() introduced in go1.16. We provide this +// wrapping to minimize client source code changes when compiling with +// or without CGo enabled. +// +// In the latter case, and toolchains prior to go1.16, it works via +// CGo wrappers for system call functions that call the C [lib]psx +// functions of these names. This ensures that the system calls +// execute simultaneously on all the pthreads of the Go (and CGo) +// combined runtime. +// +// With CGo, the psx support works in the following way: the pthread +// that is first asked to execute the syscall does so, and determines +// if it succeeds or fails. If it fails, it returns immediately +// without attempting the syscall on other pthreads. If the initial +// attempt succeeds, however, then the runtime is stopped in order for +// the same system call to be performed on all the remaining pthreads +// of the runtime. Once all pthreads have completed the syscall, the +// return codes are those obtained by the first pthread's invocation +// of the syscall. +// +// Note, there is no need to use this variant of syscall where the +// syscalls only read state from the kernel. However, since Go's +// runtime freely migrates code execution between pthreads, support of +// this type is required for any successful attempt to fully drop or +// modify the privilege of a running Go program under Linux. +// +// More info on how Linux privilege works and examples of using this +// package can be found here: +// +// https://sites.google.com/site/fullycapable +// +// WARNING: For older go toolchains (prior to go1.15), correct +// compilation of this package may require an extra workaround step: +// +// The workaround is to build with the following CGO_LDFLAGS_ALLOW in +// effect (here the syntax is that of bash for defining an environment +// variable): +// +// export CGO_LDFLAGS_ALLOW="-Wl,-?-wrap[=,][^-.@][^,]*" +// +// +// Copyright (c) 2019,20 Andrew G. Morgan +// +// The psx package is licensed with a (you choose) BSD 3-clause or +// GPL2. See LICENSE file for details. +package psx // import "kernel.org/pub/linux/libs/security/libcap/psx" diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.c b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.c new file mode 100644 index 00000000000..12dbbc56bee --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.c @@ -0,0 +1,644 @@ +/* + * Copyright (c) 2019-21 Andrew G Morgan + * + * This file contains a collection of routines that perform thread + * synchronization to ensure that a whole process is running as a + * single privilege entity - independent of the number of pthreads. + * + * The whole file would be unnecessary if glibc exported an explicit + * psx_syscall()-like function that leveraged the nptl:setxid + * mechanism to synchronize thread state over the whole process. + */ +#undef _POSIX_C_SOURCE +#define _POSIX_C_SOURCE 199309L + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "psx_syscall.h" + +/* + * psx_load_syscalls() can be weakly defined in dependent libraries to + * provide a mechanism for a library to optionally leverage this psx + * mechanism. Specifically, when libcap calls psx_load_sycalls() it + * provides a weakly declared default that maps its system calls to + * the regular system call functions. However, when linked with psx, + * this function here overrides the syscalls to be the psx ones. + */ +void psx_load_syscalls(long int (**syscall_fn)(long int, + long int, long int, long int), + long int (**syscall6_fn)(long int, + long int, long int, long int, + long int, long int, long int)) +{ + *syscall_fn = psx_syscall3; + *syscall6_fn = psx_syscall6; +} + +/* + * type to keep track of registered threads. + */ +typedef struct registered_thread_s { + struct registered_thread_s *next, *prev; + pthread_t thread; + pthread_mutex_t mu; + int pending; + int gone; +} registered_thread_t; + +static pthread_once_t psx_tracker_initialized = PTHREAD_ONCE_INIT; + +typedef enum { + _PSX_IDLE = 0, + _PSX_SETUP = 1, + _PSX_SYSCALL = 2, + _PSX_CREATE = 3, + _PSX_INFORK = 4, + _PSX_EXITING = 5, +} psx_tracker_state_t; + +/* + * This global structure holds the global coordination state for + * libcap's psx_posix_syscall() support. + */ +static struct psx_tracker_s { + int has_forked; + + pthread_mutex_t state_mu; + pthread_cond_t cond; /* this is only used to wait on 'state' changes */ + psx_tracker_state_t state; + int initialized; + int psx_sig; + + struct { + long syscall_nr; + long arg1, arg2, arg3, arg4, arg5, arg6; + int six; + int active; + } cmd; + + struct sigaction sig_action; + struct sigaction chained_action; + registered_thread_t *root; +} psx_tracker; + +/* + * psx_action_key is used for thread local storage of the thread's + * registration. + */ +pthread_key_t psx_action_key; + +/* + * psx_do_registration called locked and creates a tracker entry for + * the current thread with a TLS specific key pointing at the threads + * specific tracker. + */ +static void *psx_do_registration(void) { + registered_thread_t *node = calloc(1, sizeof(registered_thread_t)); + pthread_mutex_init(&node->mu, NULL); + node->thread = pthread_self(); + pthread_setspecific(psx_action_key, node); + node->next = psx_tracker.root; + if (node->next) { + node->next->prev = node; + } + psx_tracker.root = node; + return node; +} + +/* + * psx_posix_syscall_actor performs the system call on the targeted + * thread and signals it is no longer pending. + */ +static void psx_posix_syscall_actor(int signum, siginfo_t *info, void *ignore) { + /* bail early if this isn't something we recognize */ + if (signum != psx_tracker.psx_sig || !psx_tracker.cmd.active || + info == NULL || info->si_code != SI_TKILL || info->si_pid != getpid()) { + if (psx_tracker.chained_action.sa_sigaction != 0) { + psx_tracker.chained_action.sa_sigaction(signum, info, ignore); + } + return; + } + + if (!psx_tracker.cmd.six) { + (void) syscall(psx_tracker.cmd.syscall_nr, + psx_tracker.cmd.arg1, + psx_tracker.cmd.arg2, + psx_tracker.cmd.arg3); + } else { + (void) syscall(psx_tracker.cmd.syscall_nr, + psx_tracker.cmd.arg1, + psx_tracker.cmd.arg2, + psx_tracker.cmd.arg3, + psx_tracker.cmd.arg4, + psx_tracker.cmd.arg5, + psx_tracker.cmd.arg6); + } + + /* + * This handler can only be called on registered threads which + * have had this specific defined at start-up. (But see the + * subsequent test.) + */ + registered_thread_t *ref = pthread_getspecific(psx_action_key); + if (ref) { + pthread_mutex_lock(&ref->mu); + ref->pending = 0; + pthread_mutex_unlock(&ref->mu); + } /* + * else thread must be dying and its psx_action_key has already + * been cleaned up. + */ +} + +/* + * Some forward declarations for the initialization + * psx_syscall_start() routine. + */ +static void _psx_prepare_fork(void); +static void _psx_fork_completed(void); +static void _psx_forked_child(void); +int __wrap_pthread_create(pthread_t *thread, const pthread_attr_t *attr, + void *(*start_routine) (void *), void *arg); + +/* + * psx requires this function to be provided by the linkage wrapping. + */ +extern int __real_pthread_create(pthread_t *thread, const pthread_attr_t *attr, + void *(*start_routine) (void *), void *arg); + +/* + * psx_confirm_sigaction reconfirms that the psx handler is the first + * handler to respond to the psx signal. It assumes that + * psx_tracker.psx_sig has been set. + */ +static void psx_confirm_sigaction(void) { + sigset_t mask, orig; + struct sigaction existing_sa; + + /* + * Block interrupts while potentially rewriting the handler. + */ + sigemptyset(&mask); + sigaddset(&mask, psx_tracker.psx_sig); + sigprocmask(SIG_BLOCK, &mask, &orig); + + sigaction(psx_tracker.psx_sig, NULL, &existing_sa); + if (existing_sa.sa_sigaction != psx_posix_syscall_actor) { + memcpy(&psx_tracker.chained_action, &existing_sa, sizeof(struct sigaction)); + psx_tracker.sig_action.sa_sigaction = psx_posix_syscall_actor; + sigemptyset(&psx_tracker.sig_action.sa_mask); + psx_tracker.sig_action.sa_flags = SA_SIGINFO | SA_ONSTACK | SA_RESTART; + sigaction(psx_tracker.psx_sig, &psx_tracker.sig_action, NULL); + } + + sigprocmask(SIG_SETMASK, &orig, NULL); +} + +/* + * psx_syscall_start initializes the subsystem including initializing + * the mutex. + */ +static void psx_syscall_start(void) { + pthread_mutex_init(&psx_tracker.state_mu, NULL); + pthread_cond_init(&psx_tracker.cond, NULL); + pthread_key_create(&psx_action_key, NULL); + pthread_atfork(_psx_prepare_fork, _psx_fork_completed, _psx_forked_child); + + /* + * All sorts of things are assumed by Linux and glibc and/or musl + * about signal handlers and which can be blocked. Go has its own + * idiosyncrasies too. We tried SIGRTMAX until + * + * https://bugzilla.kernel.org/show_bug.cgi?id=210533 + * + * Our current strategy is to aggressively intercept SIGSYS. + */ + psx_tracker.psx_sig = SIGSYS; + + psx_confirm_sigaction(); + psx_do_registration(); // register the main thread. + + psx_tracker.initialized = 1; +} + +/* + * This is the only way this library globally locks. Note, this is not + * to be confused with psx_sig (interrupt) blocking - which is + * performed around thread creation and when the signal handler is + * being confirmed. + */ +static void psx_lock(void) +{ + pthread_once(&psx_tracker_initialized, psx_syscall_start); + pthread_mutex_lock(&psx_tracker.state_mu); +} + +/* + * This is the only way this library unlocks. + */ +static void psx_unlock(void) +{ + pthread_mutex_unlock(&psx_tracker.state_mu); +} + +/* + * under lock perform a state transition. + */ +static void psx_new_state(psx_tracker_state_t was, psx_tracker_state_t is) +{ + psx_lock(); + while (psx_tracker.state != was) { + pthread_cond_wait(&psx_tracker.cond, &psx_tracker.state_mu); + } + psx_tracker.state = is; + if (is == _PSX_IDLE) { + /* only announce newly idle states since that is all we wait for */ + pthread_cond_signal(&psx_tracker.cond); + } + psx_unlock(); +} + +long int psx_syscall3(long int syscall_nr, + long int arg1, long int arg2, long int arg3) { + return psx_syscall(syscall_nr, arg1, arg2, arg3); +} + +long int psx_syscall6(long int syscall_nr, + long int arg1, long int arg2, long int arg3, + long int arg4, long int arg5, long int arg6) { + return psx_syscall(syscall_nr, arg1, arg2, arg3, arg4, arg5, arg6); +} + +static void _psx_prepare_fork(void) { + /* + * obtain global lock - we don't want any syscalls while the fork + * is occurring since it may interfere with the preparation for + * the fork. + */ + psx_new_state(_PSX_IDLE, _PSX_INFORK); +} + +static void _psx_fork_completed(void) { + /* + * The only way we can get here is if state is _PSX_INFORK and was + * previously _PSX_IDLE. Now that the fork has completed, the + * parent can continue as if it hadn't happened - the forked child + * does not tie its security state to that of the parent process + * and threads. + * + * We don't strictly need to change the psx_tracker.state since we + * hold the mutex over the fork, but we do to make deadlock + * debugging easier. + */ + psx_new_state(_PSX_INFORK, _PSX_IDLE); +} + +static void _psx_forked_child(void) { + /* + * The only way we can get here is if state is _PSX_INFORK and was + * previously _PSX_IDLE. However, none of the registered threads + * exist in this newly minted child process, so we have to reset + * the tracking structure to avoid any confusion. We also scuttle + * any chance of the PSX API working on more than one thread in + * the child by leaving the state as _PSX_INFORK. We do support + * all psx_syscall()s by reverting to them being direct in the + * fork()ed child. + * + * We do this because the glibc man page for fork() suggests that + * only a subset of things will work post fork(). Specifically, + * only a "async-signal-safe functions (see signal- safety(7)) + * until such time as it calls execve(2)" can be relied upon. That + * man page suggests that you can't expect mutexes to work: "not + * async-signal-safe because it uses pthread_mutex_lock(3) + * internally.". + */ + registered_thread_t *next, *old_root; + old_root = psx_tracker.root; + psx_tracker.root = NULL; + + psx_tracker.has_forked = 1; + + for (; old_root; old_root = next) { + next = old_root->next; + memset(old_root, 0, sizeof(*old_root)); + free(old_root); + } +} + +/* + * called locked to unregister a node from the tracker. + */ +static void psx_do_unregister(registered_thread_t *node) { + if (psx_tracker.root == node) { + psx_tracker.root = node->next; + } + if (node->next) { + node->next->prev = node->prev; + } + if (node->prev) { + node->prev->next = node->next; + } + pthread_mutex_destroy(&node->mu); + memset(node, 0, sizeof(*node)); + free(node); +} + +typedef struct { + void *(*fn)(void *); + void *arg; + sigset_t sigbits; +} psx_starter_t; + +/* + * _psx_exiting is used to cleanup the node for the thread on its exit + * path. This is needed for musl libc: + * + * https://bugzilla.kernel.org/show_bug.cgi?id=208477 + * + * and likely wise for glibc too: + * + * https://sourceware.org/bugzilla/show_bug.cgi?id=12889 + */ +static void _psx_exiting(void *node) { + /* + * Until we are in the _PSX_EXITING state, we must not block the + * psx_sig interrupt for this dying thread. That is, until this + * exiting thread can set ref->gone to 1, this dying thread is + * still participating in the psx syscall distribution. + * + * See https://github.com/golang/go/issues/42494 for a situation + * where this code is called with psx_tracker.psx_sig blocked. + */ + sigset_t sigbit, orig_sigbits; + sigemptyset(&sigbit); + pthread_sigmask(SIG_UNBLOCK, &sigbit, &orig_sigbits); + sigaddset(&sigbit, psx_tracker.psx_sig); + pthread_sigmask(SIG_UNBLOCK, &sigbit, NULL); + + /* + * With psx_tracker.psx_sig unblocked we can wait until this + * thread can enter the _PSX_EXITING state. + */ + psx_new_state(_PSX_IDLE, _PSX_EXITING); + + /* + * We now indicate that this thread is no longer participating in + * the psx mechanism. + */ + registered_thread_t *ref = node; + pthread_mutex_lock(&ref->mu); + ref->gone = 1; + pthread_mutex_unlock(&ref->mu); + + /* + * At this point, we can restore the calling sigmask to whatever + * the caller thought was appropriate for a dying thread to have. + */ + pthread_sigmask(SIG_SETMASK, &orig_sigbits, NULL); + + /* + * Allow the rest of the psx system carry on as per normal. + */ + psx_new_state(_PSX_EXITING, _PSX_IDLE); +} + +/* + * _psx_start_fn is a trampoline for the intended start function, it + * is called blocked (_PSX_CREATE), but releases the block before + * calling starter->fn. Before releasing the block, the TLS specific + * attributes are initialized for use by the interrupt handler under + * the psx mutex, so it doesn't race with an interrupt received by + * this thread and the interrupt handler does not need to poll for + * that specific attribute to be present (which is problematic during + * thread shutdown). + */ +static void *_psx_start_fn(void *data) { + void *node = psx_do_registration(); + + psx_new_state(_PSX_CREATE, _PSX_IDLE); + + psx_starter_t *starter = data; + pthread_sigmask(SIG_SETMASK, &starter->sigbits, NULL); + void *(*fn)(void *) = starter->fn; + void *arg = starter->arg; + + memset(data, 0, sizeof(*starter)); + free(data); + + void *ret; + + pthread_cleanup_push(_psx_exiting, node); + ret = fn(arg); + pthread_cleanup_pop(1); + + return ret; +} + +/* + * __wrap_pthread_create is the wrapped destination of all regular + * pthread_create calls. + */ +int __wrap_pthread_create(pthread_t *thread, const pthread_attr_t *attr, + void *(*start_routine) (void *), void *arg) { + psx_starter_t *starter = calloc(1, sizeof(psx_starter_t)); + if (starter == NULL) { + perror("failed at thread creation"); + exit(1); + } + starter->fn = start_routine; + starter->arg = arg; + /* + * Until we are in the _PSX_IDLE state and locked, we must not + * block the psx_sig interrupt for this parent thread. Arrange + * that parent thread and newly created one can restore signal + * mask. + */ + sigset_t sigbit, orig_sigbits; + sigemptyset(&sigbit); + pthread_sigmask(SIG_UNBLOCK, &sigbit, &starter->sigbits); + sigaddset(&sigbit, psx_tracker.psx_sig); + pthread_sigmask(SIG_UNBLOCK, &sigbit, &orig_sigbits); + + psx_new_state(_PSX_IDLE, _PSX_CREATE); + + /* + * until the child thread has been blessed with its own TLS + * specific attribute(s) we prevent either the parent thread or + * the new one from experiencing a PSX interrupt. + */ + pthread_sigmask(SIG_BLOCK, &sigbit, NULL); + + int ret = __real_pthread_create(thread, attr, _psx_start_fn, starter); + if (ret == -1) { + psx_new_state(_PSX_CREATE, _PSX_IDLE); + memset(starter, 0, sizeof(*starter)); + free(starter); + } /* else unlock happens in _psx_start_fn */ + + /* the parent can once again receive psx interrupt signals */ + pthread_sigmask(SIG_SETMASK, &orig_sigbits, NULL); + + return ret; +} + +/* + * __psx_immediate_syscall does one syscall using the current + * process. + */ +static long int __psx_immediate_syscall(long int syscall_nr, + int count, long int *arg) { + psx_tracker.cmd.syscall_nr = syscall_nr; + psx_tracker.cmd.arg1 = count > 0 ? arg[0] : 0; + psx_tracker.cmd.arg2 = count > 1 ? arg[1] : 0; + psx_tracker.cmd.arg3 = count > 2 ? arg[2] : 0; + + if (count > 3) { + psx_tracker.cmd.six = 1; + psx_tracker.cmd.arg4 = arg[3]; + psx_tracker.cmd.arg5 = count > 4 ? arg[4] : 0; + psx_tracker.cmd.arg6 = count > 5 ? arg[5] : 0; + return syscall(syscall_nr, + psx_tracker.cmd.arg1, + psx_tracker.cmd.arg2, + psx_tracker.cmd.arg3, + psx_tracker.cmd.arg4, + psx_tracker.cmd.arg5, + psx_tracker.cmd.arg6); + } + + psx_tracker.cmd.six = 0; + return syscall(syscall_nr, psx_tracker.cmd.arg1, + psx_tracker.cmd.arg2, psx_tracker.cmd.arg3); +} + +/* + * __psx_syscall performs the syscall on the current thread and if no + * error is detected it ensures that the syscall is also performed on + * all (other) registered threads. The return code is the value for + * the first invocation. It uses a trick to figure out how many + * arguments the user has supplied. The other half of the trick is + * provided by the macro psx_syscall() in the + * file. The trick is the 7th optional argument (8th over all) to + * __psx_syscall is the count of arguments supplied to psx_syscall. + * + * User: + * psx_syscall(nr, a, b); + * Expanded by macro to: + * __psx_syscall(nr, a, b, 6, 5, 4, 3, 2, 1, 0); + * The eighth arg is now ------------------------------------^ + */ +long int __psx_syscall(long int syscall_nr, ...) { + long int arg[7]; + int i; + + va_list aptr; + va_start(aptr, syscall_nr); + for (i = 0; i < 7; i++) { + arg[i] = va_arg(aptr, long int); + } + va_end(aptr); + + int count = arg[6]; + if (count < 0 || count > 6) { + errno = EINVAL; + return -1; + } + + if (psx_tracker.has_forked) { + return __psx_immediate_syscall(syscall_nr, count, arg); + } + + psx_new_state(_PSX_IDLE, _PSX_SETUP); + psx_confirm_sigaction(); + + long int ret; + + ret = __psx_immediate_syscall(syscall_nr, count, arg); + if (ret == -1 || !psx_tracker.initialized) { + psx_new_state(_PSX_SETUP, _PSX_IDLE); + goto defer; + } + + int restore_errno = errno; + + psx_new_state(_PSX_SETUP, _PSX_SYSCALL); + psx_tracker.cmd.active = 1; + + pthread_t self = pthread_self(); + registered_thread_t *next = NULL, *ref; + + psx_lock(); + for (ref = psx_tracker.root; ref; ref = next) { + next = ref->next; + if (ref->thread == self) { + continue; + } + pthread_mutex_lock(&ref->mu); + ref->pending = 1; + int gone = ref->gone; + if (!gone) { + gone = pthread_kill(ref->thread, psx_tracker.psx_sig) != 0; + } + pthread_mutex_unlock(&ref->mu); + if (!gone) { + continue; + } + /* + * need to remove invalid thread id from linked list + */ + psx_do_unregister(ref); + } + psx_unlock(); + + for (;;) { + int waiting = 0; + psx_lock(); + for (ref = psx_tracker.root; ref; ref = next) { + next = ref->next; + if (ref->thread == self) { + continue; + } + + pthread_mutex_lock(&ref->mu); + int pending = ref->pending; + int gone = ref->gone; + if (pending && !gone) { + gone = (pthread_kill(ref->thread, 0) != 0); + } + pthread_mutex_unlock(&ref->mu); + if (!gone) { + waiting += pending; + continue; + } + /* + * need to remove invalid thread id from linked list + */ + psx_do_unregister(ref); + } + psx_unlock(); + if (!waiting) { + break; + } + sched_yield(); + } + + errno = restore_errno; + psx_tracker.cmd.active = 0; + psx_new_state(_PSX_SYSCALL, _PSX_IDLE); + +defer: + return ret; +} diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.go b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.go new file mode 100644 index 00000000000..77648e2f0ed --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx.go @@ -0,0 +1,19 @@ +// +build linux,!cgo +// +build go1.16 + +package psx // import "kernel.org/pub/linux/libs/security/libcap/psx" + +import "syscall" + +// Documentation for these functions are provided in the psx_cgo.go +// file. + +//go:uintptrescapes +func Syscall3(syscallnr, arg1, arg2, arg3 uintptr) (uintptr, uintptr, syscall.Errno) { + return syscall.AllThreadsSyscall(syscallnr, arg1, arg2, arg3) +} + +//go:uintptrescapes +func Syscall6(syscallnr, arg1, arg2, arg3, arg4, arg5, arg6 uintptr) (uintptr, uintptr, syscall.Errno) { + return syscall.AllThreadsSyscall6(syscallnr, arg1, arg2, arg3, arg4, arg5, arg6) +} diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_cgo.go b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_cgo.go new file mode 100644 index 00000000000..26aa15a474f --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_cgo.go @@ -0,0 +1,79 @@ +// +build linux,cgo + +package psx // import "kernel.org/pub/linux/libs/security/libcap/psx" + +import ( + "runtime" + "syscall" +) + +// #cgo LDFLAGS: -lpthread -Wl,-wrap,pthread_create +// +// #include +// #include "psx_syscall.h" +// +// long __errno_too(long set_errno) { +// long v = errno; +// if (set_errno >= 0) { +// errno = set_errno; +// } +// return v; +// } +import "C" + +// setErrno returns the current C.errno value and, if v >= 0, sets the +// CGo errno for a random pthread to value v. If you want some +// consistency, this needs to be called from runtime.LockOSThread() +// code. This function is only defined for testing purposes. The psx.c +// code should properly handle the case that a non-zero errno is saved +// and restored independently of what these Syscall[36]() functions +// observe. +func setErrno(v int) int { + return int(C.__errno_too(C.long(v))) +} + +//go:uintptrescapes + +// Syscall3 performs a 3 argument syscall. Syscall3 differs from +// syscall.[Raw]Syscall() insofar as it is simultaneously executed on +// every thread of the combined Go and CGo runtimes. It works +// differently depending on whether CGO_ENABLED is 1 or 0 at compile +// time. +// +// If CGO_ENABLED=1 it uses the libpsx function C.psx_syscall3(). +// +// If CGO_ENABLED=0 it redirects to the go1.16+ +// syscall.AllThreadsSyscall() function. +func Syscall3(syscallnr, arg1, arg2, arg3 uintptr) (uintptr, uintptr, syscall.Errno) { + // We lock to the OSThread here because we may need errno to + // be the one for this thread. + runtime.LockOSThread() + defer runtime.UnlockOSThread() + + v := C.psx_syscall3(C.long(syscallnr), C.long(arg1), C.long(arg2), C.long(arg3)) + var errno syscall.Errno + if v < 0 { + errno = syscall.Errno(C.__errno_too(-1)) + } + return uintptr(v), uintptr(v), errno +} + +//go:uintptrescapes + +// Syscall6 performs a 6 argument syscall on every thread of the +// combined Go and CGo runtimes. Other than the number of syscall +// arguments, its behavior is identical to that of Syscall3() - see +// above for the full documentation. +func Syscall6(syscallnr, arg1, arg2, arg3, arg4, arg5, arg6 uintptr) (uintptr, uintptr, syscall.Errno) { + // We lock to the OSThread here because we may need errno to + // be the one for this thread. + runtime.LockOSThread() + defer runtime.UnlockOSThread() + + v := C.psx_syscall6(C.long(syscallnr), C.long(arg1), C.long(arg2), C.long(arg3), C.long(arg4), C.long(arg5), C.long(arg6)) + var errno syscall.Errno + if v < 0 { + errno = syscall.Errno(C.__errno_too(-1)) + } + return uintptr(v), uintptr(v), errno +} diff --git a/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_syscall.h b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_syscall.h new file mode 100644 index 00000000000..4aacfabdfb1 --- /dev/null +++ b/vendor/kernel.org/pub/linux/libs/security/libcap/psx/psx_syscall.h @@ -0,0 +1,74 @@ +/* + * Copyright (c) 2019 Andrew G. Morgan + * + * This header, and the -lpsx library, provide a number of things to + * support POSIX semantics for syscalls associated with the pthread + * library. Linking this code is tricky and is done as follows: + * + * ld ... -lpsx -lpthread --wrap=pthread_create + * or, gcc ... -lpsx -lpthread -Wl,-wrap,pthread_create + * + * glibc provides a subset of this functionality natively through the + * nptl:setxid mechanism and could implement psx_syscall() directly + * using that style of functionality but, as of 2019-11-30, the setxid + * mechanism is limited to 9 specific set*() syscalls that do not + * support the syscall6 API (needed for prctl functions and the ambient + * capabilities set for example). + */ + +#ifndef _SYS_PSX_SYSCALL_H +#define _SYS_PSX_SYSCALL_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include + +/* + * psx_syscall performs the specified syscall on all psx registered + * threads. The mechanism by which this occurs is much less efficient + * than a standard system call on Linux, so it should only be used + * when POSIX semantics are required to change process relevant + * security state. + * + * Glibc has native support for POSIX semantics on setgroups() and the + * 8 set*[gu]id() functions. So, there is no need to use psx_syscall() + * for these calls. This call exists for all the other system calls + * that need to maintain parity on all pthreads of a program. + * + * Some macrology is used to allow the caller to provide only as many + * arguments as needed, thus psx_syscall() cannot be used as a + * function pointer. For those situations, we define psx_syscall3() + * and psx_syscall6(). + */ +#define psx_syscall(syscall_nr, ...) \ + __psx_syscall(syscall_nr, __VA_ARGS__, (long int) 6, (long int) 5, \ + (long int) 4, (long int) 3, (long int) 2, \ + (long int) 1, (long int) 0) +long int __psx_syscall(long int syscall_nr, ...); +long int psx_syscall3(long int syscall_nr, + long int arg1, long int arg2, long int arg3); +long int psx_syscall6(long int syscall_nr, + long int arg1, long int arg2, long int arg3, + long int arg4, long int arg5, long int arg6); + +/* + * This function should be used by systems to obtain pointers to the + * two syscall functions provided by the PSX library. A linkage trick + * is to define this function as weak in a library that can optionally + * use libpsx and then, should the caller link -lpsx, that library can + * implicitly use these POSIX semantics syscalls. See libcap for an + * example of this useage. + */ +void psx_load_syscalls(long int (**syscall_fn)(long int, + long int, long int, long int), + long int (**syscall6_fn)(long int, + long int, long int, long int, + long int, long int, long int)); + +#ifdef __cplusplus +} +#endif + +#endif /* _SYS_PSX_SYSCALL_H */ diff --git a/vendor/modules.txt b/vendor/modules.txt index a0e87062072..a6b5d192a16 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -36,6 +36,10 @@ github.com/docker/go-units # github.com/godbus/dbus/v5 v5.1.0 ## explicit; go 1.12 github.com/godbus/dbus/v5 +# github.com/landlock-lsm/go-landlock v0.0.0-20210828133255-ec6c6b87a946 +## explicit; go 1.16 +github.com/landlock-lsm/go-landlock/landlock +github.com/landlock-lsm/go-landlock/landlock/syscall # github.com/moby/sys/capability v0.4.0 ## explicit; go 1.21 github.com/moby/sys/capability @@ -116,3 +120,6 @@ google.golang.org/protobuf/reflect/protoreflect google.golang.org/protobuf/reflect/protoregistry google.golang.org/protobuf/runtime/protoiface google.golang.org/protobuf/runtime/protoimpl +# kernel.org/pub/linux/libs/security/libcap/psx v1.2.51 +## explicit; go 1.11 +kernel.org/pub/linux/libs/security/libcap/psx