Affected: Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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…

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…

Security update for the Linux Kernel

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 154 more

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 [ 7…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, darunter möglicherweise die Ausführung von beliebigem Code, die Ausweitung von Berechtigungen, die Offenlegung von Informationen, die Manipulation von Daten oder Denial-of-Service-Zustände.