CVE-2026-68204
Description
In the Linux kernel, the following vulnerability has been resolved: media: vivid: check for vb2_is_busy() when toggling caps The vivid_update_format_cap/out() functions must only be called if the capture/output queue are not busy. But for the controls that select the CROP/COMPOSE/SCALE capability that is not checked. Only when streaming starts will they be set to 'grabbed' and it is impossible to change the control, but between REQBUFS and STREAMON you are still allowed to set these controls. Since vivid_update_format_cap/out will change the format, this can cause unexpected results. Besides adding these checks, also add a WARN_ON in vivid_update_format_cap/out() if the queue is busy. I'm 90% certain that this is the cause of this syzbot bug: https://syzkaller.appspot.com/bug?extid=dac8f5eaa46837e97b89 But since we never have reproducers, it is hard to be certain. In any case, these checks are needed regardless.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://git.kernel.org/stable/c/a9cd0e8fb0b21faaa71199d9d3feb305c18ff576
- https://git.kernel.org/stable/c/abaec6747304581f8d4a9936352fa10e13325f07
- https://git.kernel.org/stable/c/492c97cb50feaa60ccd7792d3d6b904ed8ec61bf
- https://git.kernel.org/stable/c/daf2d92669b4a659d805d88d811161c70cd325ee
- https://git.kernel.org/stable/c/c2d1a2130c93f6d758af58590b86b2254c7a1dec
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.