Cloudanix VulnDB

CVE-2026-68281

None

CVSS

—

EPSS

0.2%

Published

Aug 10, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A graphics driver bug can cause the system to log errors or delay graphics work when handling certain paired drawing tasks.

Exploitation
Local Privilege
Attacker needs
Low Privilege
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

The prepare_job() callback undercounts remaining native dependencies for paired geometry and fragment jobs, allowing run_job() to submit incomplete command sequences to an almost-full CCCB and triggering kernel warnings or job timeouts.

Why it matters to the business

Graphics workloads on affected hardware may fail or stall, producing log warnings and reducing reliability of applications that depend on the GPU.

How an attack unfolds

A local attacker submits paired geometry and fragment jobs in rapid succession so that the dependency between them is not yet visible to the firmware check, causing the scheduler to underestimate queue space and write a truncated command stream.

How to fix it

Upgrade the Linux kernel to a version that includes the corrected job_count_remaining_native_deps() logic in the imagination/pvr driver.

How to confirm the fix worked

Confirm the presence of the updated pvr_queue_submit_job_to_cccb and job_count_remaining_native_deps functions; re-test paired job submission under high queue occupancy to ensure no early unblocking occurs.

Typical attack path

  1. Obtain local execution on a system with the vulnerable PowerVR DRM driver
  2. Create and submit paired geometry and fragment jobs that race with the dependency tracking logic
  3. Trigger the underestimated queue space check and force an early return from run_job()
  4. Observe resulting kernel warnings or application-visible job timeouts

How to detect it

Search kernel logs for the exact warning string emitted by pvr_cccb_write_command_with_header when the CCCB write is truncated; correlate with powervr-sched workqueue activity.

  • WARNING: drivers/gpu/drm/imagination/pvr_cccb.c:178 at pvr_cccb_write_command_with_header
  • pvr_queue_run_job+0x3a4/0x990 [powervr]
  • drm_sched_run_job_work+0x580/0xd48 [gpu_sched]

What your security team should do

  • Apply the kernel update containing the paired-job dependency fix at the earliest maintenance window
  • Add kernel log monitoring for pvr_cccb_write_command_with_header warnings
  • Restrict unprivileged access to DRM render nodes until the fix is deployed

The record

In the Linux kernel, the following vulnerability has been resolved: drm/imagination: Count paired job fence as dependency in prepare_job() The DRM scheduler's prepare_job() callback counts the remaining non-signaled native dependencies for a job, preventing job submission until those (plus job data and fence update) can fit in the job queue's CCCB. This means checking which dependencies can be waited upon in the firmware, i.e. whether they are backed by a UFO object, i.e. whether their drm_sched_fence::parent has been assigned to a pvr_queue_fence::base fence. That happens when the job owning the fence is submitted to the firmware. Paired geometry and fragment jobs are submitted at the same time, which means the dependency between them can't be checked this way before submission. Update job_count_remaining_native_deps() to take into account the dependency between paired jobs. This fixes cases where prepare_job() underestimated the space left in an almost full fragment CCCB, wrongly unblocking run_job(), which then returned early without writing the full sequence of commands to the CCCB. The above lead to kernel warnings such as the following and potentially job timeouts (depending on waiters on the missing commands): [ 375.702979] WARNING: drivers/gpu/drm/imagination/pvr_cccb.c:178 at pvr_cccb_write_command_with_header+0x2c4/0x330 [powervr], CPU#1: kworker/u16:3/47 [ 375.703160] Modules linked in: [ 375.703571] CPU: 1 UID: 0 PID: 47 Comm: kworker/u16:3 Tainted: G W 7.0.0-rc2-g817eb6b11ad5 #40 PREEMPT [ 375.703613] Tainted: [W]=WARN [ 375.703627] Hardware name: Texas Instruments AM625 SK (DT) [ 375.703645] Workqueue: powervr-sched drm_sched_run_job_work [gpu_sched] [ 375.703741] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 375.703764] pc : pvr_cccb_write_command_with_header+0x2c4/0x330 [powervr] [ 375.703847] lr : pvr_queue_submit_job_to_cccb+0x578/0xa70 [powervr] [ 375.703921] sp : ffff800084a97650 [ 375.703934] x29: ffff800084a97740 x28: 0000000000000958 x27: ffff80008565d000 [ 375.703979] x26: 0000000000000030 x25: ffff800084a97680 x24: 0000000000001000 [ 375.704017] x23: ffff800084a97820 x22: 1ffff00010952ecc x21: 0000000000000008 [ 375.704056] x20: 00000000000006a8 x19: ffff00002ff7da88 x18: 0000000000000000 [ 375.704093] x17: 0000000020020000 x16: 0000000000020000 x15: 0000000000000000 [ 375.704132] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [ 375.704168] x11: 000000000000f2f2 x10: 00000000f3000000 x9 : 00000000f3f3f3f3 [ 375.704206] x8 : 00000000f2f2f200 x7 : ffff700010952ecc x6 : 0000000000000008 [ 375.704243] x5 : 0000000000000000 x4 : 1ffff00010acba00 x3 : 0000000000000000 [ 375.704279] x2 : 0000000000000007 x1 : 0000000000000fff x0 : 000000000000002f [ 375.704317] Call trace: [ 375.704331] pvr_cccb_write_command_with_header+0x2c4/0x330 [powervr] (P) [ 375.704411] pvr_queue_submit_job_to_cccb+0x578/0xa70 [powervr] [ 375.704487] pvr_queue_run_job+0x3a4/0x990 [powervr] [ 375.704562] drm_sched_run_job_work+0x580/0xd48 [gpu_sched] [ 375.704623] process_one_work+0x520/0x1288 [ 375.704658] worker_thread+0x3f0/0xb3c [ 375.704680] kthread+0x334/0x3d8 [ 375.704706] ret_from_fork+0x10/0x20 [ 375.704736] ---[ end trace 0000000000000000 ]---

Affected packages

Ecosystem Package Introduced Fixed