wifi: nl80211: reject cooked mode if it is set along with other flags
In the Linux kernel, the following vulnerability has been resolved: wifi: nl80211: reject cooked mode if it is set along with other flags It is possible to set both MONITOR_FLAG_COOK_FRAMES and MONITOR_FLAG_ACTIVE flags simultaneously on the same monitor interface from the userspace. This causes a sub-interface to be created with no IEEE80211_SDATA_IN_DRIVER bit set because the monitor interface is in the cooked state and it takes precedence over all other states. When the interface is then being deleted the kernel calls WARN_ONCE() from check_sdata_in_driver() because of missing that bit. Fix this by rejecting MONITOR_FLAG_COOK_FRAMES if it is set along with other flags. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: wifi: nl80211: reject cooked mode if it is set along with other flags It is possible to set both MONITOR_FLAG_COOK_FRAMES and MONITOR_FLAG_ACTIVE flags simultaneously on the same monitor interface from the userspace. This causes a sub-interface to be created with no IEEE80211_SDATA_IN_DRIVER bit set because the monitor interface is in the cooked state and it takes precedence over all other states. When the interface is then being deleted the kernel calls WARN_ONCE() from check_sdata_in_driver() because of missing that bit. Fix this by rejecting MONITOR_FLAG_COOK_FRAMES if it is set along with other flags. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/236f41ca728f23210b31ed2d1d8a6df575a4b2d6
- https://git.kernel.org/stable/c/351eb7ac53ff1cd94d893c0c4534ced2f36ae7d7
- https://git.kernel.org/stable/c/49f27f29446a5bfe633dd2cc0cfebd48a1a5e77f
- https://git.kernel.org/stable/c/521e55c2b0d6028861ac0a2d06aa57bb0e3ac486
- https://git.kernel.org/stable/c/5ea856d93794c4afa5542defd8c61f2708dc245a
- https://git.kernel.org/stable/c/ac4860141300581d3e2f6c6dafa37220f7ea9f65
- https://git.kernel.org/stable/c/cd1bdcb77fdc03c253137e55bae10551b3481461
- https://git.kernel.org/stable/c/ebebbb0eded2ed9a1abfa31962f6fb699e6abce7
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21909.json
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- https://nvd.nist.gov/vuln/detail/CVE-2025-21909