CVE-2025-40258

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