The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x dc30c011469165d57af9adac5baff7d767d20e5c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023041101-slackness-maturing-0041@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
dc30c0114691 ("drm/i915: fix race condition UAF in i915_perf_add_config_ioctl") 2fec539112e8 ("i915/perf: Replace DRM_DEBUG with driver specific drm_dbg call")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From dc30c011469165d57af9adac5baff7d767d20e5c Mon Sep 17 00:00:00 2001 From: Min Li lm0963hack@gmail.com Date: Tue, 28 Mar 2023 17:36:27 +0800 Subject: [PATCH] drm/i915: fix race condition UAF in i915_perf_add_config_ioctl
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-lm0963ha... [tursulin: Manually added stable tag.] (cherry picked from commit 49f6f6483b652108bcb73accd0204a464b922395) Signed-off-by: Jani Nikula jani.nikula@intel.com
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 283a4a3c6862..004074936300 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -4638,13 +4638,13 @@ 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);