segfault caused in cog-drm-modeset-renderer.c

[dangowrt]

Shortly after (correctly!) displaying page content cog 0.19.1 crashes with DRM/KMS backend on aarch64-linux-linux.

Thread 1 "cog" received signal SIGSEGV, Segmentation fault.
0x0000007ff04a17c4 in drm_copy_shm_buffer_into_bo (
    shm_buffer=shm_buffer@entry=0x7fc3f94ad0, bo=0x7fc3f52e60)
    at ../platform/drm/cog-drm-modeset-renderer.c:306

line 306:

                dst[bo_stride * y + 4 * x + 0] = src[stride * y + 4 * x + 0];

When running under a wayland compositor (e.g. weston) the problem does occur.