CVE-2025-39826

Published: September 17, 2025Last modified: September 17, 2025

Description

In the Linux kernel, the following vulnerability has been resolved: net: rose: convert 'use' field to refcount_t The 'use' field in struct rose_neigh is used as a reference counter but lacks atomicity. This can lead to race conditions where a rose_neigh structure is freed while still being referenced by other code paths. For example, when rose_neigh->use becomes zero during an ioctl operation via rose_rt_ioctl(), the structure may be removed while its timer is still active, potentially causing use-after-free issues. This patch changes the type of 'use' from unsigned short to refcount_t and updates all code paths to use rose_neigh_hold() and rose_neigh_put() which operate reference counts atomically.

Status

References

• https://git.kernel.org/stable/c/0085b250fcc79f900c82a69980ec2f3e1871823b
• https://git.kernel.org/stable/c/203e4f42596ede31498744018716a3db6dbb7f51
• https://git.kernel.org/stable/c/d860d1faa6b2ce3becfdb8b0c2b048ad31800061
• https://git.kernel.org/stable/c/f8c29fc437d03a98fb075c31c5be761cc8326284
• https://git.kernel.org/stable/c/fb07156cc0742ba4e93dfcc84280c011d05b301f
• https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html