CVE-2026-68263 drm/imagination: Fix double call to drm_sched_entity_fini()
A double free in the Imagination DRM driver causes a use-after-free, allowing local attackers to execute code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68263?
CVE-2026-68263 is a high-severity use after free vulnerability in Linux, published on 10 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drm/imagination: Fix double call to drm_sched_entity_fini()
Call sequence of double call: pvr_context_destroy pvr_context_kill_queues pvr_queue_kill drm_sched_entity_destroy drm_sched_entity_fini // here pvr_context_put kref_put(..., pvr_context_release) pvr_context_destroy_queues pvr_queue_destroy drm_sched_entity_fini // here
Call to drm_sched_entity_destroy() from pvr_context_kill_queues() calls drm_sched_entity_flush() + drm_sched_entity_fini(). drm_sched_entity_flush() ensures all pending jobs are completed and drm_sched_entity_fini() ensures no further submission is allowed as per expectation from pvr_context_kill_queues(). Double call to drm_sched_entity_fini() is misuse of the API so keep call only in pvr_context_create() failure path.
Stack trace for issue with addition of refcounting for DRM entity stats in commit fd177135f0e6 ("drm/sched: Account entity GPU time"):
[ 789.490527] ------------[ cut here ]------------ [ 789.490559] refcount_t: underflow; use-after-free. [ 789.490657] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xf4/0x144, CPU#0: kworker/u16:1/440 [ 789.490695] Modules linked in: powervr drm_gpuvm drm_exec gpu_sched drm_shmem_helper xhci_plat_hcd xhci_hcd dwc3 usbcore usb_common snd_soc_simple_card snd_soc_simple_card_utils sa2ul sha512 sha256 dwc3_am62 sha1 authenc rti_wdt libsha512 at24 sch_fq_codel fuse dm_mod ipv6 [ 789.490798] CPU: 0 UID: 0 PID: 440 Comm: kworker/u16:1 Not tainted 7.0.0-rc7-02049-g5e2c0700091b #22 PREEMPT [ 789.490809] Hardware name: Texas Instruments AM625 SK (DT) [ 789.490815] Workqueue: powervr-sched pvr_queue_fence_release_work [powervr] [ 789.490868] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 789.490876] pc : refcount_warn_saturate+0xf4/0x144 [ 789.490884] lr : refcount_warn_saturate+0xf4/0x144 [ 789.490892] sp : ffff8000822cbcc0 [ 789.490895] x29: ffff8000822cbcc0 x28: 0000000000000000 x27: 0000000000000000 [ 789.490909] x26: 0000000000000000 x25: ffff800081b1e338 x24: ffff000004541405 [ 789.490922] x23: ffff000004bea950 x22: ffff00000042e400 x21: ffff000007123e30 [ 789.490935] x20: ffff000007123000 x19: ffff000007a80d50 x18: fffffffffffe7768 [ 789.490948] x17: 74736574202c6e6f x16: 697461746e656d65 x15: ffff800081b269f0 [ 789.490962] x14: 0000000000000030 x13: ffff800081b26a70 x12: 0000000000000211 [ 789.490975] x11: 00000000000000c0 x10: 0000000000000b50 x9 : ffff8000822cbb30 [ 789.490988] x8 : ffff0000014e7bb0 x7 : ffff00007725e780 x6 : 0000000372a05f49 [ 789.491001] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000010 [ 789.491013] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000014e7000 [ 789.491027] Call trace: [ 789.491032] refcount_warn_saturate+0xf4/0x144 (P) [ 789.491043] drm_sched_entity_fini+0x164/0x18c [gpu_sched] [ 789.491081] pvr_queue_destroy+0x64/0x134 [powervr] [ 789.491110] pvr_context_destroy_queues+0x34/0x64 [powervr] [ 789.491138] pvr_context_release+0x70/0xac [powervr] [ 789.491166] pvr_context_put.part.0+0x5c/0x7c [powervr] [ 789.491193] pvr_context_put+0x14/0x24 [powervr] [ 789.491221] pvr_queue_fence_release_work+0x20/0x38 [powervr] [ 789.491249] process_one_work+0x160/0x4c4 [ 789.491264] worker_thread+0x188/0x310 [ 789.491276] kthread+0x130/0x13c [ 789.491287] ret_from_fork+0x10/0x20 [ 789.491300] ---[ end trace 0000000000000000 ]---
Which versions are affected by CVE-2026-68263?
How do I fix CVE-2026-68263?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-68263 being exploited?
There is no known exploitation of CVE-2026-68263 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68263, DEBIAN-CVE-2026-68263, GHSA-x35m-7ch7-75hq, UBUNTU-CVE-2026-68263.