============================================ WARNING: possible recursive locking detected 6.1.113-syzkaller #0 Not tainted -------------------------------------------- syz.3.1684/8806 is trying to acquire lock: ffff88805d9bed88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88805d9bed88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0x13a/0x210 net/hsr/hsr_device.c:219 but task is already holding lock: ffff88801ef78d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88801ef78d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x272/0xad0 net/hsr/hsr_device.c:300 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&hsr->seqnr_lock); lock(&hsr->seqnr_lock); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz.3.1684/8806: #0: ffffc900001e0bc0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc2/0x6b0 kernel/time/timer.c:1501 #1: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: hsr_announce+0x9f/0x340 net/hsr/hsr_device.c:377 #2: ffff88801ef78d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff88801ef78d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x272/0xad0 net/hsr/hsr_device.c:300 #3: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #3: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: hsr_forward_skb+0xaa/0x2390 net/hsr/hsr_forward.c:614 #4: ffffffff8d32b020 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #4: ffffffff8d32b020 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:843 [inline] #4: ffffffff8d32b020 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3d50 net/core/dev.c:4220 #5: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #5: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #5: ffffffff8d32afc0 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x212/0x18e0 net/bridge/br_device.c:49 #6: ffffffff8d32b020 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #6: ffffffff8d32b020 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:843 [inline] #6: ffffffff8d32b020 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3d50 net/core/dev.c:4220 stack backtrace: CPU: 1 PID: 8806 Comm: syz.3.1684 Not tainted 6.1.113-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2983 [inline] check_deadlock kernel/locking/lockdep.c:3026 [inline] validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x13a/0x210 net/hsr/hsr_device.c:219 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 __dev_queue_xmit+0x1b5d/0x3d50 net/core/dev.c:4297 dev_queue_xmit include/linux/netdevice.h:3021 [inline] br_dev_queue_push_xmit+0x6fe/0x8c0 net/bridge/br_forward.c:53 NF_HOOK+0x39f/0x450 include/linux/netfilter.h:302 br_forward_finish+0xe1/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x39f/0x450 include/linux/netfilter.h:302 __br_forward+0x430/0x5f0 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:189 br_flood+0x2e7/0x440 net/bridge/br_forward.c:231 br_dev_xmit+0x1194/0x18e0 __netdev_start_xmit include/linux/netdevice.h:4853 [inline] netdev_start_xmit include/linux/netdevice.h:4867 [inline] xmit_one net/core/dev.c:3627 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643 __dev_queue_xmit+0x1b5d/0x3d50 net/core/dev.c:4297 dev_queue_xmit include/linux/netdevice.h:3021 [inline] hsr_xmit net/hsr/hsr_forward.c:380 [inline] hsr_forward_do net/hsr/hsr_forward.c:471 [inline] hsr_forward_skb+0x17f3/0x2390 net/hsr/hsr_forward.c:619 send_hsr_supervision_frame+0x540/0xad0 net/hsr/hsr_device.c:323 hsr_announce+0x1a4/0x340 net/hsr/hsr_device.c:379 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 __do_softirq kernel/softirq.c:605 [inline] invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5120 Code: 38 0b 00 48 83 c4 08 4c 89 f7 e8 68 31 00 00 0f 1f 44 00 00 4c 89 f7 e8 1b 36 52 09 e8 d6 f2 31 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc9000402f2c8 EFLAGS: 00000282 RAX: ed340e3f36c2c400 RBX: ffff888027a1bbb4 RCX: ffffffff97337103 RDX: dffffc0000000000 RSI: ffffffff8b0c02c0 RDI: ffff88807a70d178 RBP: ffffc9000402f310 R08: dffffc0000000000 R09: ffffed10171e7539 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807a70bb80 R13: 1ffff110171e76e3 R14: ffff8880b8f3a9c0 R15: ffff8880b8f3b718 context_switch kernel/sched/core.c:5244 [inline] __schedule+0x1447/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0xac/0x300 kernel/time/timer.c:1941 unix_wait_for_peer+0x24b/0x330 net/unix/af_unix.c:1443 unix_dgram_sendmsg+0x1348/0x2050 net/unix/af_unix.c:2022 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2519 ___sys_sendmsg net/socket.c:2573 [inline] __sys_sendmmsg+0x3ab/0x730 net/socket.c:2659 __do_sys_sendmmsg net/socket.c:2688 [inline] __se_sys_sendmmsg net/socket.c:2685 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1e8cd7dff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1e8db4f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f1e8cf35f80 RCX: 00007f1e8cd7dff9 RDX: 0000000000000651 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007f1e8cdf0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1e8cf35f80 R15: 00007ffe61af77d8 sched: RT throttling activated ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 0b 00 or (%rax),%eax 2: 48 83 c4 08 add $0x8,%rsp 6: 4c 89 f7 mov %r14,%rdi 9: e8 68 31 00 00 call 0x3176 e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 13: 4c 89 f7 mov %r14,%rdi 16: e8 1b 36 52 09 call 0x9523636 1b: e8 d6 f2 31 00 call 0x31f2f6 20: fb sti 21: 49 8d bc 24 f8 15 00 lea 0x15f8(%r12),%rdi 28: 00 * 29: 48 89 f8 mov %rdi,%rax <-- trapping instruction 2c: 48 c1 e8 03 shr $0x3,%rax 30: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 37: fc ff df 3a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax