CVE-2025-40258

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Source
https://cve.org/CVERecord?id=CVE-2025-40258
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40258.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-40258
Downstream
Related
Published
2025-12-04T16:08:19Z
Modified
2026-08-12T03:30:46Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
mptcp: fix race condition in mptcp_schedule_work()
Details

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: __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

Database specific 
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40258.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
3b1d6210a9577369103330b0d802b0bf74b65e7f
Fixed
f865e6595acf33083168db76921e66ace8bf0e5b
Fixed
99908e2d601236842d705d5fd04fb349577316f5
Fixed
db4f7968a75250ca6c4ed70d0a78beabb2dcee18
Fixed
8f9ba1a99a89feef9b5867c15a0141a97e893309
Fixed
ac28dfddedf6f209190950fc71bcff65ec4ab47b
Fixed
3fc7723ed01d1130d4bf7063c50e0af60ecccbb4
Fixed
035bca3f017ee9dea3a5a756e77a6f7138cc6eea

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40258.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.7.0
Fixed
5.10.247
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.197
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.159
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.118
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.60
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.17.10

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-40258.json"