9p/net: fix improper handling of bogus negative read/write replies
In the Linux kernel, the following vulnerability has been resolved: 9p/net: fix improper handling of bogus negative read/write replies In p9_client_write() and p9_client_read_once(), if the server incorrectly replies with success but a negative write/read count then we would consider written (negative) <= rsize (positive) because both variables were signed. Make variables unsigned to avoid this problem. The reproducer linked below now fails with the following error instead of a null pointer deref: 9pnet: bogus RWRITE count (4294967295 > 3)
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: 9p/net: fix improper handling of bogus negative read/write replies In p9_client_write() and p9_client_read_once(), if the server incorrectly replies with success but a negative write/read count then we would consider written (negative) <= rsize (positive) because both variables were signed. Make variables unsigned to avoid this problem. The reproducer linked below now fails with the following error instead of a null pointer deref: 9pnet: bogus RWRITE count (4294967295 > 3)
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/374e4cd75617c8c2552f562f39dd989583f5c330
- https://git.kernel.org/stable/c/468ff4a7c61fb811c596a7c44b6a5455e40fd12b
- https://git.kernel.org/stable/c/a68768e280b7d0c967ea509e791bb9b90adc94a5
- https://git.kernel.org/stable/c/c548f95688e2b5ae0e2ae43d53cf717156c7d034
- https://git.kernel.org/stable/c/d0259a856afca31d699b706ed5e2adf11086c73b
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/37xxx/CVE-2025-37879.json
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- https://nvd.nist.gov/vuln/detail/CVE-2025-37879