CVE-2025-39962

rxrpc: Fix untrusted unsigned subtract

State: Published
Severity: 7.5 High
Published: Oct 9, 2025
Updated: Aug 5, 2026
Reserved: Apr 16, 2025

Description

In the Linux kernel, the following vulnerability has been resolved:

rxrpc: Fix untrusted unsigned subtract

Fix the following Smatch static checker warning:

net/rxrpc/rxgk_app.c:65 rxgk_yfs_decode_ticket() warn: untrusted unsigned subtract. 'ticket_len - 10 * 4'

by prechecking the length of what we're trying to extract in two places in the token and decoding for a response packet.

Also use sizeof() on the struct we're extracting rather specifying the size numerically to be consistent with the other related statements.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a to before 71571e187106631a8127f2dde780f35caa358d33Affected 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a to before 2429a197648178cd4dc930a9d87c13c547460564Affected
LinuxLinux	6.16Affected before 6.16Not affected 6.16.9 through 6.16.*Not affected 6.17 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.