CVE-2026-68263

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/imagination: Fix double call to drm_sched_entity_fini()<br /> <br /> Call sequence of double call:<br /> pvr_context_destroy<br />   pvr_context_kill_queues<br />     pvr_queue_kill<br />       drm_sched_entity_destroy<br />         drm_sched_entity_fini // here<br />   pvr_context_put<br />     kref_put(..., pvr_context_release)<br />       pvr_context_destroy_queues<br />         pvr_queue_destroy<br />           drm_sched_entity_fini // here<br /> <br /> Call to drm_sched_entity_destroy() from pvr_context_kill_queues() calls<br /> drm_sched_entity_flush() + drm_sched_entity_fini().<br /> drm_sched_entity_flush() ensures all pending jobs are completed and<br /> drm_sched_entity_fini() ensures no further submission is allowed as<br /> per expectation from pvr_context_kill_queues(). Double call to<br /> drm_sched_entity_fini() is misuse of the API so keep call only in<br /> pvr_context_create() failure path.<br /> <br /> Stack trace for issue with addition of refcounting for DRM entity<br /> stats in commit fd177135f0e6 ("drm/sched: Account entity GPU time"):<br /> <br /> [ 789.490527] ------------[ cut here ]------------<br /> [ 789.490559] refcount_t: underflow; use-after-free.<br /> [ 789.490657] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0xf4/0x144, CPU#0: kworker/u16:1/440<br /> [ 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<br /> [ 789.490798] CPU: 0 UID: 0 PID: 440 Comm: kworker/u16:1 Not tainted 7.0.0-rc7-02049-g5e2c0700091b #22 PREEMPT<br /> [ 789.490809] Hardware name: Texas Instruments AM625 SK (DT)<br /> [ 789.490815] Workqueue: powervr-sched pvr_queue_fence_release_work [powervr]<br /> [ 789.490868] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)<br /> [ 789.490876] pc : refcount_warn_saturate+0xf4/0x144<br /> [ 789.490884] lr : refcount_warn_saturate+0xf4/0x144<br /> [ 789.490892] sp : ffff8000822cbcc0<br /> [ 789.490895] x29: ffff8000822cbcc0 x28: 0000000000000000 x27: 0000000000000000<br /> [ 789.490909] x26: 0000000000000000 x25: ffff800081b1e338 x24: ffff000004541405<br /> [ 789.490922] x23: ffff000004bea950 x22: ffff00000042e400 x21: ffff000007123e30<br /> [ 789.490935] x20: ffff000007123000 x19: ffff000007a80d50 x18: fffffffffffe7768<br /> [ 789.490948] x17: 74736574202c6e6f x16: 697461746e656d65 x15: ffff800081b269f0<br /> [ 789.490962] x14: 0000000000000030 x13: ffff800081b26a70 x12: 0000000000000211<br /> [ 789.490975] x11: 00000000000000c0 x10: 0000000000000b50 x9 : ffff8000822cbb30<br /> [ 789.490988] x8 : ffff0000014e7bb0 x7 : ffff00007725e780 x6 : 0000000372a05f49<br /> [ 789.491001] x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000010<br /> [ 789.491013] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000014e7000<br /> [ 789.491027] Call trace:<br /> [ 789.491032] refcount_warn_saturate+0xf4/0x144 (P)<br /> [ 789.491043] drm_sched_entity_fini+0x164/0x18c [gpu_sched]<br /> [ 789.491081] pvr_queue_destroy+0x64/0x134 [powervr]<br /> [ 789.491110] pvr_context_destroy_queues+0x34/0x64 [powervr]<br /> [ 789.491138] pvr_context_release+0x70/0xac [powervr]<br /> [ 789.491166] pvr_context_put.part.0+0x5c/0x7c [powervr]<br /> [ 789.491193] pvr_context_put+0x14/0x24 [powervr]<br /> [ 789.491221] pvr_queue_fence_release_work+0x20/0x38 [powervr]<br /> [ 789.491249] process_one_work+0x160/0x4c4<br /> [ 789.491264] worker_thread+0x188/0x310<br /> [ 789.491276] kthread+0x130/0x13c<br /> [ 789.491287] ret_from_fork+0x10/0x20<br /> [ 789.491300] ---[ end trace 0000000000000000 ]---