CVE-2025-37824

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tipc: fix NULL pointer dereference in tipc_mon_reinit_self()<br /> <br /> syzbot reported:<br /> <br /> tipc: Node number set to 1055423674<br /> Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI<br /> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]<br /> CPU: 3 UID: 0 PID: 6017 Comm: kworker/3:5 Not tainted 6.15.0-rc1-syzkaller-00246-g900241a5cc15 #0 PREEMPT(full)<br /> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014<br /> Workqueue: events tipc_net_finalize_work<br /> RIP: 0010:tipc_mon_reinit_self+0x11c/0x210 net/tipc/monitor.c:719<br /> ...<br /> RSP: 0018:ffffc9000356fb68 EFLAGS: 00010246<br /> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003ee87cba<br /> RDX: 0000000000000000 RSI: ffffffff8dbc56a7 RDI: ffff88804c2cc010<br /> RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000<br /> R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000007<br /> R13: fffffbfff2111097 R14: ffff88804ead8000 R15: ffff88804ead9010<br /> FS: 0000000000000000(0000) GS:ffff888097ab9000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00000000f720eb00 CR3: 000000000e182000 CR4: 0000000000352ef0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> tipc_net_finalize+0x10b/0x180 net/tipc/net.c:140<br /> process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238<br /> process_scheduled_works kernel/workqueue.c:3319 [inline]<br /> worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400<br /> kthread+0x3c2/0x780 kernel/kthread.c:464<br /> ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153<br /> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245<br /> <br /> ...<br /> RIP: 0010:tipc_mon_reinit_self+0x11c/0x210 net/tipc/monitor.c:719<br /> ...<br /> RSP: 0018:ffffc9000356fb68 EFLAGS: 00010246<br /> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003ee87cba<br /> RDX: 0000000000000000 RSI: ffffffff8dbc56a7 RDI: ffff88804c2cc010<br /> RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000<br /> R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000007<br /> R13: fffffbfff2111097 R14: ffff88804ead8000 R15: ffff88804ead9010<br /> FS: 0000000000000000(0000) GS:ffff888097ab9000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00000000f720eb00 CR3: 000000000e182000 CR4: 0000000000352ef0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> <br /> There is a racing condition between workqueue created when enabling<br /> bearer and another thread created when disabling bearer right after<br /> that as follow:<br /> <br /> enabling_bearer | disabling_bearer<br /> --------------- | ----------------<br /> tipc_disc_timeout() |<br /> { | bearer_disable()<br /> ... | {<br /> schedule_work(&amp;tn-&gt;work); | tipc_mon_delete()<br /> ... | {<br /> } | ...<br /> | write_lock_bh(&amp;mon-&gt;lock);<br /> | mon-&gt;self = NULL;<br /> | write_unlock_bh(&amp;mon-&gt;lock);<br /> | ...<br /> | }<br /> tipc_net_finalize_work() | }<br /> { |<br /> ... |<br /> tipc_net_finalize() |<br /> { |<br /> ... |<br /> tipc_mon_reinit_self() |<br /> { |<br /> ... |<br /> write_lock_bh(&amp;mon-&gt;lock); |<br /> mon-&gt;self-&gt;addr = tipc_own_addr(net); |<br /> write_unlock_bh(&amp;mon-&gt;lock); |<br /> ... <br /> ---truncated---