============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- kworker/u4:20/7757 is trying to acquire lock: ffff88801e6c89e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88801e6c89e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0x15c/0x550 net/unix/garbage.c:413 but task is already holding lock: ffff88801e6c81e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88801e6c81e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0xb7/0x550 net/unix/garbage.c:405 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rlock-AF_UNIX); lock(rlock-AF_UNIX); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by kworker/u4:20/7757: #0: ffff888018479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc9000c7b7d00 (unix_gc_work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8ec57558 (unix_gc_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffffffff8ec57558 (unix_gc_lock){+.+.}-{2:2}, at: __unix_gc+0xcb/0x1100 net/unix/garbage.c:589 #3: ffff88801e6c81e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff88801e6c81e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: unix_collect_skb+0xb7/0x550 net/unix/garbage.c:405 stack backtrace: CPU: 1 PID: 7757 Comm: kworker/u4:20 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Workqueue: events_unbound __unix_gc Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3090 [inline] validate_chain kernel/locking/lockdep.c:3884 [inline] __lock_acquire+0x690e/0x7ea0 kernel/locking/lockdep.c:5171 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] unix_collect_skb+0x15c/0x550 net/unix/garbage.c:413 __unix_walk_scc net/unix/garbage.c:520 [inline] unix_walk_scc net/unix/garbage.c:551 [inline] __unix_gc+0x868/0x1100 net/unix/garbage.c:601 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 sd 0:0:1:0: cmd ffff8880286b9720 CDB: 0x2a Added buffer head 34 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b9ae0 CDB: 0x2a Added buffer head 79 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b9ea0 CDB: 0x2a Added buffer head 32 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286ba260 CDB: 0x2a Added buffer head 20 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286ba620 CDB: 0x2a Added buffer head 15 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286ba9e0 CDB: 0x2a Added buffer head 56 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bada0 CDB: 0x2a Added buffer head 82 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bb160 CDB: 0x2a Added buffer head 76 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bb520 CDB: 0x2a Added buffer head 71 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bb8e0 CDB: 0x2a Added buffer head 88 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bbca0 CDB: 0x2a Added buffer head 23 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bc060 CDB: 0x2a Added buffer head 7 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b9360 CDB: 0x2a Added buffer head 34 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286bc420 CDB: 0x2a Added buffer head 2 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b8be0 CDB: 0x2a Added buffer head 25 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b8fa0 CDB: 0x2a Added buffer head 110 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b8820 CDB: 0x2a Added buffer head 27 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b80a0 CDB: 0x2a Added buffer head 70 to ffff888140185a00 sd 0:0:1:0: cmd ffff8880286b8460 CDB: 0x2a Added buffer head 29 to ffff888140185a00 nf_conntrack: new packet for ffff888046744300 nf_nat: Already setup manip DST for ct ffff888046744300 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff888046744300 (status bits 0x188) nf_conntrack: new packet for ffff88802f3dec00 nf_nat: Already setup manip DST for ct ffff88802f3dec00 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff88802f3dec00 (status bits 0x188) nf_conntrack: new packet for ffff88802039dc80 nf_nat: Already setup manip DST for ct ffff88802039dc80 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff88802039dc80 (status bits 0x188) nf_conntrack: new packet for ffff88807586d200 nf_nat: Already setup manip DST for ct ffff88807586d200 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff88807586d200 (status bits 0x188) wireguard: wg2: Sending handshake initiation to peer 23 ([::1]:20001/0%0) nf_conntrack: new packet for ffff88802f3ded80 nf_nat: Already setup manip DST for ct ffff88802f3ded80 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff88802f3ded80 (status bits 0x188) nf_conntrack: new packet for ffff888046744300 nf_nat: Already setup manip DST for ct ffff888046744300 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff888046744300 (status bits 0x188) nf_conntrack: new packet for ffff8880784bd980 nf_nat: Already setup manip DST for ct ffff8880784bd980 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff8880784bd980 (status bits 0x188) nf_conntrack: new packet for ffff888046744780 nf_nat: Already setup manip DST for ct ffff888046744780 (status bits 0x188) nf_nat: Already setup manip SRC for ct ffff888046744780 (status bits 0x188)