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4c6a23188e
Once drm_framebuffer_init has returned 0, the framebuffer is hooked up
to the reference counting machinery and can no longer be destroyed with
a simple kfree. Therefore, it must be called last.
If drm_framebuffer_init returns 0 but its caller then returns non-0,
there will likely be memory corruption fireworks down the road.
The following lead me to this fix:
[ 12.891228] kernel BUG at lib/list_debug.c:25!
[...]
[ 12.891263] RIP: 0010:__list_add_valid+0x4b/0x70
[...]
[ 12.891324] Call Trace:
[ 12.891330] drm_framebuffer_init+0xb5/0x100 [drm]
[ 12.891378] amdgpu_display_gem_fb_verify_and_init+0x47/0x120 [amdgpu]
[ 12.891592] ? amdgpu_display_user_framebuffer_create+0x10d/0x1f0 [amdgpu]
[ 12.891794] amdgpu_display_user_framebuffer_create+0x126/0x1f0 [amdgpu]
[ 12.891995] drm_internal_framebuffer_create+0x378/0x3f0 [drm]
[ 12.892036] ? drm_internal_framebuffer_create+0x3f0/0x3f0 [drm]
[ 12.892075] drm_mode_addfb2+0x34/0xd0 [drm]
[ 12.892115] ? drm_internal_framebuffer_create+0x3f0/0x3f0 [drm]
[ 12.892153] drm_ioctl_kernel+0xe2/0x150 [drm]
[ 12.892193] drm_ioctl+0x3da/0x460 [drm]
[ 12.892232] ? drm_internal_framebuffer_create+0x3f0/0x3f0 [drm]
[ 12.892274] amdgpu_drm_ioctl+0x43/0x80 [amdgpu]
[ 12.892475] __se_sys_ioctl+0x72/0xc0
[ 12.892483] do_syscall_64+0x33/0x40
[ 12.892491] entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixes: f258907fdd "drm/amdgpu: Verify bo size can fit framebuffer size on init."
Signed-off-by: Michel Dänzer <mdaenzer@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Linux kernel
============
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