kernel panic in generic_file_write

[dvyukov]

Got this while running syzkaller on 2b284c4:

bash-4.3$ kernel panic at kern/src/vfs.c:1359, from core 1: assertion failed: buf == buf_end
Entering Nanwan's Dungeon on Core 1 (Ints on):
Type 'help' for a list of commands.
ROS(Core 1)> bash-4.3$ bt
Stack Backtrace on Core 1:
#01 [<0xffffffffc2016074>] in mon_backtrace
#02 [<0xffffffffc2017177>] in monitor
#03 [<0xffffffffc200cbfc>] in _panic
#04 [<0xffffffffc205c51c>] in generic_file_write
#05 [<0xffffffffc2053890>] in sys_write
#06 [<0xffffffffc2056919>] in syscall
#07 [<0xffffffffc2056ad4>] in run_local_syscall
#08 [<0xffffffffc20a28aa>] in sysenter_callwrapper

Unfortunately our ability to localize and produce reproducers is limited due to no Go support.

[akaros-notifier]

On 2017-11-01 at 16:41 Dmitry Vyukov ***@***.***> wrote: Unfortunately our ability to localize and produce reproducers is limited due to no Go support.

Yeah, that makes it a little rough. Do you have a log of what the syscall arguments were? Even something like the last 100 calls would help.

[akaros-notifier]

On 2017-11-01 at 14:55 Barret Rhoden ***@***.***> wrote: Do you have a log of what the syscall arguments were? Even something like the last 100 calls would help.

Alternatively, I can run the syzkaller. Is there an easy way to seed it or something so I can have it make the same calls that it did for you? If not, no big deal. For this particular bug, I might be able to solve it by looking at the code (might be an assumption that breaks for misaligned writes or something), but it'd be nice to have some path to repeating the bug so anyone can try and fix it. Of course, a working Go 1.9 would be nice too. =)

[akaros-notifier]

Has the Go port been updated since I last updated it to 1.3 many moons ago? Kevin

…

On Thu, Nov 2, 2017 at 5:23 PM Barret Rhoden ***@***.***> wrote: On 2017-11-01 at 14:55 Barret Rhoden ***@***.***> wrote: > Do you have a log of what the syscall arguments were? Even something > like the last 100 calls would help. Alternatively, I can run the syzkaller. Is there an easy way to seed it or something so I can have it make the same calls that it did for you? If not, no big deal. For this particular bug, I might be able to solve it by looking at the code (might be an assumption that breaks for misaligned writes or something), but it'd be nice to have some path to repeating the bug so anyone can try and fix it. Of course, a working Go 1.9 would be nice too. =) -- You received this message because you are subscribed to the Google Groups "Akaros" group. To unsubscribe from this group and stop receiving emails from it, send an email to ***@***.*** To post to this group, send email to ***@***.*** For more options, visit https://groups.google.com/d/optout.

[dvyukov]

No, because you did not accept my pull request :)
akaros/go-akaros#1

But seriously, unfortunately that won't help as we need Go 1.9+.

[brho]

Sorry! I didn't see your pull request in the go-akaros repo.