Messages in this thread | | | Date | Wed, 29 Mar 2023 10:20:32 +0100 | Subject | Re: [PATCH 1/1] drm/i915: fix race condition UAF in i915_perf_add_config_ioctl | From | Tvrtko Ursulin <> |
| |
On 29/03/2023 01:48, Umesh Nerlige Ramappa wrote: > On Tue, Mar 28, 2023 at 02:08:47PM +0100, Tvrtko Ursulin wrote: >> >> On 28/03/2023 10:36, Min Li wrote: >>> 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: Lionel Landwerlin <lionel.g.landwerlin@intel.com> >> Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com> >> Cc: <stable@vger.kernel.org> # v4.14+ >> >>> --- >>> drivers/gpu/drm/i915/i915_perf.c | 6 +++--- >>> 1 file changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/i915/i915_perf.c >>> b/drivers/gpu/drm/i915/i915_perf.c >>> index 824a34ec0b83..93748ca2c5da 100644 >>> --- a/drivers/gpu/drm/i915/i915_perf.c >>> +++ b/drivers/gpu/drm/i915/i915_perf.c >>> @@ -4634,13 +4634,13 @@ int i915_perf_add_config_ioctl(struct >>> drm_device *dev, void *data, >>> err = oa_config->id; >>> goto sysfs_err; >>> } >>> - >>> - mutex_unlock(&perf->metrics_lock); >>> + id = oa_config->id; >>> drm_dbg(&perf->i915->drm, >>> "Added config %s id=%i\n", oa_config->uuid, oa_config->id); >>> + mutex_unlock(&perf->metrics_lock); >>> - return oa_config->id; >>> + return id; >>> sysfs_err: >>> mutex_unlock(&perf->metrics_lock); >> >> LGTM. >> >> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> >> >> Umesh or Lionel could you please double check? I can merge if >> confirmed okay. > > LGTM, > > Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Pushed to drm-intel-gt-next, thanks for the fix and reviews!
Regards,
Tvrtko
| |