CVE-2026-68217: In the Linux kernel, the following vulnerability has been resolved: media: pwc: Drain fill_buf on start_streaming() failure pwc_isoc_init() submits ...

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/

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 885fe18f5542fe283a17f70583383c6cadcba1c3, < a56e7641e09bd80b976e944ae759109b86fd5b38; >= 885fe18f5542fe283a17f70583383c6cadcba1c3, < acc789b2173070638cad89c2b61d33ed338be0dd; >= 885fe18f5542fe283a17f70583383c6cadcba1c3, < 9afd605dcd96c7a45f338eded1de16679b30e1df; >= 885fe18f5542fe283a17f70583383c6cadcba1c3, < 5d4812668b03f823b5044789d6aa77fe56b42587; >= 885fe18f5542fe283a17f70583383c6cadcba1c3, < 906e410dcffbbd99fb4081abab817a830033aa28
Linux	Linux	3.1

References

Timeline

Published: Aug 10, 2026
Last Modified: Aug 10, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-68217?

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/

How severe is CVE-2026-68217?

Severity scoring for CVE-2026-68217 is pending analysis.

How do I fix CVE-2026-68217?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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