CVE-2025-37879

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

Description

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)

N/A

CVSS

Severity:

EPSS 0.02%

Affected: Linux Linux

References

Link	Tags
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/374e4cd75617c8c2552f562f39dd989583f5c330
https://git.kernel.org/stable/c/d0259a856afca31d699b706ed5e2adf11086c73b

Frequently Asked Questions

What is the severity of CVE-2025-37879?: CVE-2025-37879 has not yet been assigned a CVSS score.
How to fix CVE-2025-37879?: To fix CVE-2025-37879, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-37879 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2025-37879 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-37879?: CVE-2025-37879 affects Linux Linux, Linux Linux.

This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.