CVE-2025-37879

Summary

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)

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products we track (2)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/374e4cd75617c8c2552f562f39dd989583f5c330 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/374e4cd75617c8c2552f562f39dd989583f5c330Patch
• https://git.kernel.org/stable/c/468ff4a7c61fb811c596a7c44b6a5455e40fd12bPatch
• https://git.kernel.org/stable/c/a68768e280b7d0c967ea509e791bb9b90adc94a5Patch
• https://git.kernel.org/stable/c/c548f95688e2b5ae0e2ae43d53cf717156c7d034Patch
• https://git.kernel.org/stable/c/d0259a856afca31d699b706ed5e2adf11086c73bPatch
• https://lists.debian.org/debian-lts-announce/2025/05/msg00045.htmlAdvisory