9p/net: fix improper handling of bogus negative read/write replies
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.8epss 0.7%
exploitation probability
0.7%top 51% of all CVEs
observed exploitation
nono source reports it
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)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
Linux · LinuxReferences
https://git.kernel.org/stable/c/374e4cd75617c8c2552f562f39dd989583f5c330https://git.kernel.org/stable/c/468ff4a7c61fb811c596a7c44b6a5455e40fd12bhttps://git.kernel.org/stable/c/a68768e280b7d0c967ea509e791bb9b90adc94a5https://git.kernel.org/stable/c/c548f95688e2b5ae0e2ae43d53cf717156c7d034https://git.kernel.org/stable/c/d0259a856afca31d699b706ed5e2adf11086c73bhttps://lists.debian.org/debian-lts-announce/2025/05/msg00045.html