CVE-2025-40231

NameCVE-2025-40231
DescriptionIn the Linux kernel, the following vulnerability has been resolved: vsock: fix lock inversion in vsock_assign_transport() Syzbot reported a potential lock inversion deadlock between vsock_register_mutex and sk_lock-AF_VSOCK when vsock_linger() is called. The issue was introduced by commit 687aa0c5581b ("vsock: Fix transport_* TOCTOU") which added vsock_register_mutex locking in vsock_assign_transport() around the transport->release() call, that can call vsock_linger(). vsock_assign_transport() can be called with sk_lock held. vsock_linger() calls sk_wait_event() that temporarily releases and re-acquires sk_lock. During this window, if another thread hold vsock_register_mutex while trying to acquire sk_lock, a circular dependency is created. Fix this by releasing vsock_register_mutex before calling transport->release() and vsock_deassign_transport(). This is safe because we don't need to hold vsock_register_mutex while releasing the old transport, and we ensure the new transport won't disappear by obtaining a module reference first via try_module_get().
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bullseye5.10.223-1vulnerable
bullseye (security)5.10.244-1vulnerable
bookworm6.1.148-1vulnerable
bookworm (security)6.1.158-1fixed
trixie6.12.57-1fixed
trixie (security)6.12.48-1vulnerable
forky6.17.9-1fixed
sid6.17.10-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebookworm6.1.158-1
linuxsourcetrixie6.12.57-1
linuxsource(unstable)6.17.6-1

Notes

https://git.kernel.org/linus/f7c877e7535260cc7a21484c994e8ce7e8cb6780 (6.18-rc3)

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