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VulnerabilityPublished Updated

CVE-2026-68217: Linux kernel · media: pwc: Drain fill_buf on start_streaming() failure

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity
Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS
0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +55

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-38.38
Fixed in
  • 7.0.0-38.38
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1017.17
Fixed in
  • 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1016.16
Fixed in
  • 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1008.9
Fixed in
  • 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: media: pwc: Drain fill_buf on start_streaming() failure pwc_isoc_init() submits its isochronous URBs with usb_submit_urb(.., GFP_KERNEL) in a loop. After the first URB is submitted, its completion handler pwc_isoc_handler() can run on another CPU before the loop finishes: start_streaming() pwc_isoc_init() usb_submit_urb(urbs[0], GFP_KERNEL) pwc_isoc_handler(urbs[0]) pdev->fill_buf = pwc_get_next_fill_buf(pdev) usb_submit_urb(urbs[i>0], ..) -> fails pwc_isoc_cleanup(pdev) /* kills URBs */ return ret; pwc_cleanup_queued_bufs(pdev, VB2_BUF_STATE_QUEUED) pwc_get_next_fill_buf() detaches a buffer from pdev->queued_bufs and stores it in pdev->fill_buf. The error path in start_streaming() only drains pdev->queued_bufs, so the buffer parked in pdev->fill_buf is leaked. vb2_start_streaming() then triggers WARN_ON(owned_by_drv_count). stop_streaming() already handles this since commit 80b0963e1698 ("[media] pwc: fix WARN_ON"), which added the fill_buf drain in the teardown path but not in the start_streaming() error path. Mirror that handling on failure so start_streaming() returns with no buffer owned by the driver. Issue identified by automated review of the INV-003 series at https://sashiko.dev/

References

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