Am 07.09.23 um 16:47 schrieb Thomas Hellström:
Hi,
On 9/7/23 16:37, Christian König wrote:
Am 07.09.23 um 15:53 schrieb Thomas Hellström:
While trying to replicate a weird drm_exec lock alloc tracking warning
using the drm_exec kunit test, the warning was shadowed by a UAF
warning
from KASAN due to a bug in the drm kunit helpers.
Patch 1 fixes that drm kunit UAF.
Patch 2 introduces a drm_exec kunit subtest that fails if the
conditions
for the weird warning are met.
The series previously also had a patch with a drm_exec workaround
for the
warning but that patch has already been commited to
drm_misc_next_fixes.
Thinking more about this what happens when somebody calls
drm_exec_unlock_obj() on the first locked object?
Essentially the same thing. I've been thinking of the best way to
handle that, but not sure what's the best one.
Well what does lockdep store in that object in the first place? Could we
fix that somehow?
Christian.
/Thomas
Christian.
v2:
- Rewording of commit messages
- Add some commit message tags
v3:
- Remove an already committed patch
- Rework the test to not require dmesg inspection (Maxime Ripard)
- Condition the test on CONFIG_LOCK_ALLOC
- Update code comments and commit messages (Maxime Ripard)
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Thomas Hellström (2):
drm/tests: helpers: Avoid a driver uaf
drm/tests/drm_exec: Add a test for object freeing within
drm_exec_fini()
drivers/gpu/drm/tests/drm_exec_test.c | 82
+++++++++++++++++++++++++++
include/drm/drm_kunit_helpers.h | 4 +-
2 files changed, 85 insertions(+), 1 deletion(-)
