by Kastro
Paper/Archive/CVE-2025-37879

CVE-2025-37879

Linux Linux — 9p/net: fix improper handling of bogus negative read/write replies

EPSS 0.7%CVSS 9.8
critical.is priorityof 100
40
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 53.9.539 × 2010.8No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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)

Affected

ProductAffectedFixed inSource
Linux070b3656cf228eaaef7b28b59264c5c7cdbdd0fb – < 468ff4a7c61fb811c596a7c44b6a5455e40fd12b468ff4a7c61fb811c596a7c44b6a5455e40fd12bCNA
Linux070b3656cf228eaaef7b28b59264c5c7cdbdd0fb – < a68768e280b7d0c967ea509e791bb9b90adc94a5a68768e280b7d0c967ea509e791bb9b90adc94a5CNA
Linux070b3656cf228eaaef7b28b59264c5c7cdbdd0fb – < c548f95688e2b5ae0e2ae43d53cf717156c7d034c548f95688e2b5ae0e2ae43d53cf717156c7d034CNA
Linux070b3656cf228eaaef7b28b59264c5c7cdbdd0fb – < 374e4cd75617c8c2552f562f39dd989583f5c330374e4cd75617c8c2552f562f39dd989583f5c330CNA
Linux070b3656cf228eaaef7b28b59264c5c7cdbdd0fb – < d0259a856afca31d699b706ed5e2adf11086c73bd0259a856afca31d699b706ed5e2adf11086c73bCNA
Linux4.1–CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

refgit.kernel.org/stable/c/468ff4a7c61fb811c596a7c44b6a5455e40fd12brefgit.kernel.org/stable/c/a68768e280b7d0c967ea509e791bb9b90adc94a5refgit.kernel.org/stable/c/c548f95688e2b5ae0e2ae43d53cf717156c7d034refgit.kernel.org/stable/c/374e4cd75617c8c2552f562f39dd989583f5c330refgit.kernel.org/stable/c/d0259a856afca31d699b706ed5e2adf11086c73breflists.debian.org/debian-lts-announce/2025/05/msg00045.html