drm: fix send_vblank_event use-after-free error
The drm_pending_event can be freed by drm_send_event_locked, as a
result we should call trace_drm_vblank_event_delivered before this
to avoid hitting a user-after-free error when accessing the pid member:
[ 378.438497] BUG: KASAN: use-after-free in send_vblank_event+0xf0/0x310 [drm] at addr ffff8801ac7e50a0
[ 378.438500] Read of size 4 by task Xorg/1562
[ 378.438501] =============================================================================
[ 378.438504] BUG kmalloc-128 (Tainted: G B ): kasan: bad access detected
[ 378.438506] -----------------------------------------------------------------------------
[ 378.438509] INFO: Freed in 0x10001309c age=18446737369265680575 cpu=0 pid=0
[ 378.438541] drm_send_event_locked+0x207/0x2f0 [drm]
[ 378.438544] __slab_free+0x24c/0x650
[ 378.438546] kfree+0x3a2/0x760
[ 378.438578] drm_send_event_locked+0x207/0x2f0 [drm]
[ 378.438610] send_vblank_event+0xb7/0x310 [drm]
[ 378.438643] drm_crtc_send_vblank_event+0x130/0x1f0 [drm]
[ 378.438722] intel_atomic_commit_tail+0x23b5/0x53f0 [i915]
[ 378.438802] intel_atomic_commit+0xbae/0x12f0 [i915]
[ 378.438839] drm_atomic_commit+0xb0/0x120 [drm]
[ 378.438855] drm_atomic_helper_connector_dpms+0x339/0x5d0 [drm_kms_helper]
[ 378.438891] drm_mode_obj_set_property_ioctl+0x8f1/0xcc0 [drm]
[ 378.438927] drm_mode_connector_property_set_ioctl+0xf3/0x170 [drm]
[ 378.438959] drm_ioctl+0x2d7/0xae0 [drm]
[ 378.438962] do_vfs_ioctl+0x1c9/0x1280
[ 378.438964] SyS_ioctl+0x79/0x90
[ 378.438967] entry_SYSCALL_64_fastpath+0x1a/0xa4
Cc: dri-devel@lists.freedesktop.org
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466440966-5410-1-git-send-email-matthew.auld@intel.com
1 file changed