CVE-2025-40258mptcp: fix race condition in mptcp_schedule_work()
- 9.8CriticalCVSS base score
- 0.50%Exploitation in 30 daysEPSS · top 57% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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
Timeline
ID reserved
By Linux
- 8 months later
· 8 months later
Published
- 8 months later
· 8 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.50% · top 57% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < f865e6595acf33083168db76921e66ace8bf0e5b
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < 99908e2d601236842d705d5fd04fb349577316f5
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < db4f7968a75250ca6c4ed70d0a78beabb2dcee18
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < 8f9ba1a99a89feef9b5867c15a0141a97e893309
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < ac28dfddedf6f209190950fc71bcff65ec4ab47b
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < 3fc7723ed01d1130d4bf7063c50e0af60ecccbb4
- affected 3b1d6210a9577369103330b0d802b0bf74b65e7f – < 035bca3f017ee9dea3a5a756e77a6f7138cc6eea
- affected 5.7
- unaffected < 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.*
- unaffected 6.12.60 – ≤ 6.12.*
- unaffected 6.17.10 – ≤ 6.17.*
- unaffected 6.18 – ≤ *
References
References8
- https://git.kernel.org/stable/c/f865e6595acf33083168db76921e66ace8bf0e5b (opens in a new tab)
- https://git.kernel.org/stable/c/99908e2d601236842d705d5fd04fb349577316f5 (opens in a new tab)
- https://git.kernel.org/stable/c/db4f7968a75250ca6c4ed70d0a78beabb2dcee18 (opens in a new tab)
- https://git.kernel.org/stable/c/8f9ba1a99a89feef9b5867c15a0141a97e893309 (opens in a new tab)
- https://git.kernel.org/stable/c/ac28dfddedf6f209190950fc71bcff65ec4ab47b (opens in a new tab)
- https://git.kernel.org/stable/c/3fc7723ed01d1130d4bf7063c50e0af60ecccbb4 (opens in a new tab)
- https://git.kernel.org/stable/c/035bca3f017ee9dea3a5a756e77a6f7138cc6eea (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-253495.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-201199 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-40258)Record last updated .