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)
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4193-1 linux-6.1 security update
EUVD EUVD EUVD-2025-14111 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)
Ubuntu USN Ubuntu USN USN-7594-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7594-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7594-3 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 12 Nov 2025 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Linux
Linux linux Kernel
Weaknesses CWE-125
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}


Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00026}

epss

{'score': 0.00027}


Sat, 10 May 2025 02:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Fri, 09 May 2025 07:00:00 +0000

Type Values Removed Values Added
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)
Title 9p/net: fix improper handling of bogus negative read/write replies
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-11-03T19:56:51.125Z

Reserved: 2025-04-16T04:51:23.962Z

Link: CVE-2025-37879

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-05-09T07:16:09.143

Modified: 2025-11-12T19:53:46.030

Link: CVE-2025-37879

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-05-09T00:00:00Z

Links: CVE-2025-37879 - Bugzilla

cve-icon OpenCVE Enrichment

No data.