Min Li 6eeb1cba4c drm/i915: fix race condition UAF in i915_perf_add_config_ioctl
[ Upstream commit dc30c011469165d57af9adac5baff7d767d20e5c ]

Userspace can guess the id value and try to race oa_config object creation
with config remove, resulting in a use-after-free if we dereference the
object after unlocking the metrics_lock.  For that reason, unlocking the
metrics_lock must be done after we are done dereferencing the object.

Signed-off-by: Min Li <lm0963hack@gmail.com>
Fixes: f89823c21224 ("drm/i915/perf: Implement I915_PERF_ADD/REMOVE_CONFIG interface")
Cc: <stable@vger.kernel.org> # v4.14+
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230328093627.5067-1-lm0963hack@gmail.com
[tursulin: Manually added stable tag.]
(cherry picked from commit 49f6f6483b652108bcb73accd0204a464b922395)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20 12:13:55 +02:00
..