Commit 28aeaed1 authored by Sanjay Yadav's avatar Sanjay Yadav Committed by Matthew Auld
Browse files

drm/xe/oa: Fix potential UAF in xe_oa_add_config_ioctl() 

In xe_oa_add_config_ioctl(), we accessed oa_config->id after dropping
metrics_lock. Since this lock protects the lifetime of oa_config, an
attacker could guess the id and call xe_oa_remove_config_ioctl() with
perfect timing, freeing oa_config before we dereference it, leading to
a potential use-after-free.

Fix this by caching the id in a local variable while holding the lock.

v2: (Matt A)
- Dropped mutex_unlock(&oa->metrics_lock) ordering change from
  xe_oa_remove_config_ioctl()

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6614


Fixes: cdf02fe1 ("drm/xe/oa/uapi: Add/remove OA config perf ops")
Cc: <stable@vger.kernel.org> # v6.11+
Suggested-by: default avatarMatthew Auld <matthew.auld@intel.com>
Signed-off-by: default avatarSanjay Yadav <sanjay.kumar.yadav@intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20251118114859.3379952-2-sanjay.kumar.yadav@intel.com
parent 423fb66f

drivers/gpu/drm/xe/xe_oa.c

+5 −3
Original line number Diff line number Diff line
@@ -2403,11 +2403,13 @@ int xe_oa_add_config_ioctl(struct drm_device *dev, u64 data, struct drm_file *fi 
		goto sysfs_err;

	}



	mutex_unlock(&oa->metrics_lock);

	id = oa_config->id;



	drm_dbg(&oa->xe->drm, "Added config %s id=%i\n", oa_config->uuid, id);



	drm_dbg(&oa->xe->drm, "Added config %s id=%i\n", oa_config->uuid, oa_config->id);

	mutex_unlock(&oa->metrics_lock);



	return oa_config->id;

	return id;



sysfs_err:

	mutex_unlock(&oa->metrics_lock);