media: vivid: check for vb2_is_busy() when toggling caps
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
3.18
References 8
git.kernel.org
- stable/c/0a820f03727b509b887f3216a574062948761f34
- stable/c/bbc96bc75de0fcd9bb6ac48798b206e3b09ec865
- stable/c/6a5bc8aea111ccbca71ef2b9c868d5c81f2e89de
- stable/c/a9cd0e8fb0b21faaa71199d9d3feb305c18ff576
- stable/c/abaec6747304581f8d4a9936352fa10e13325f07
- stable/c/492c97cb50feaa60ccd7792d3d6b904ed8ec61bf
- stable/c/daf2d92669b4a659d805d88d811161c70cd325ee
- stable/c/c2d1a2130c93f6d758af58590b86b2254c7a1dec