Vigie VulnDBEuropean-hosted Vulnerability DB

CVE-2025-40258

mptcp: fix race condition in mptcp_schedule_work()

At a glance

Severity
CRITICAL 9.8
EPSS
EPSS 0.46 % · percentile 40 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Deferred

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix race condition in mptcp_schedule_work() syzbot reported use-after-free in mptcp_schedule_work() [1] Issue here is that mptcp_schedule_work() schedules a work, then gets a refcount on sk->sk_refcnt if the work was scheduled. This refcount will be released by mptcp_worker(). [A] if (schedule_work(...)) { [B] sock_hold(sk); return true; } Problem is that mptcp_worker() can run immediately and complete before [B] We need instead : sock_hold(sk); if (schedule_work(...)) return true; sock_put(sk); [1] refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 29 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25 Call Trace: <TASK> __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] sock_hold include/net/sock.h:816 [inline] mptcp_schedule_work+0x164/0x1a0 net/mptcp/protocol.c:943 mptcp_tout_timer+0x21/0xa0 net/mptcp/protocol.c:2316 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x648/0x970 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x22f/0x710 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0xcf/0x190 kernel/softirq.c:1138 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Scores

VersionScoreVectorScored by
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux
CVSS 3.1CRITICAL 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)

European references

CERT-FR advisories

Affected products

ProductVersions
Linux · Linuxaffected 3b1d6210a9577369103330b0d802b0bf74b65e7f < f865e6595acf33083168db76921e66ace8bf0e5b ; affected 3b1d6210a9577369103330b0d802b0bf74b65e7f < 99908e2d601236842d705d5fd04fb349577316f5 ; affected 3b1d6210a9577369103330b0d802b0bf74b65e7f < db4f7968a75250ca6c4ed70d0a78beabb2dcee18 ; affected 3b1d6210a9577369103330b0d802b0bf74b65e7f < 8f9ba1a99a89feef9b5867c15a0141a97e893309 ; affected 3b1d6210a9577369103330b0d802b0bf74b65e7f < ac28dfddedf6f209190950fc71bcff65ec4ab47b ; affected 3b1d6210a9577369103330b0d802b0bf74b65e7f < 3fc7723ed01d1130d4bf7063c50e0af60ecccbb4
Linux · Linuxaffected 5.7 ; unaffected 0 < 5.7 ; unaffected 5.10.247 ≤ 5.10.* ; unaffected 5.15.197 ≤ 5.15.* ; unaffected 6.1.159 ≤ 6.1.* ; unaffected 6.6.118 ≤ 6.6.*

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD