Commit 16536582 authored by Matthew Auld's avatar Matthew Auld
Browse files

drm/xe/queue: move xa_alloc to prevent UAF 



Evil user can guess the next id of the queue before the ioctl completes
and then call queue destroy ioctl to trigger UAF since create ioctl is
still referencing the same queue. Move the xa_alloc all the way to the end
to prevent this.

v2:
 - Rebase

Fixes: 2149ded6 ("drm/xe: Fix use after free when client stats are captured")
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarNirmoy Das <nirmoy.das@intel.com>
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240925071426.144015-4-matthew.auld@intel.com
parent dcfd3971

drivers/gpu/drm/xe/xe_exec_queue.c

+3 −1
Original line number Diff line number Diff line
@@ -635,12 +635,14 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data, 
		}

	}



	q->xef = xe_file_get(xef);



	/* user id alloc must always be last in ioctl to prevent UAF */

	err = xa_alloc(&xef->exec_queue.xa, &id, q, xa_limit_32b, GFP_KERNEL);

	if (err)

		goto kill_exec_queue;



	args->exec_queue_id = id;

	q->xef = xe_file_get(xef);



	return 0;