============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------- syz-fuzzer/5075 is trying to acquire lock: ffff88805d46cda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88805d46cda0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0x13e/0x1d0 net/hsr/hsr_device.c:229 but task is already holding lock: ffff8880186d4da0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880186d4da0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x276/0xad0 net/hsr/hsr_device.c:310 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-fuzzer/5075: #0: ffffc90000a08c00 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789 #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_announce+0xa3/0x370 net/hsr/hsr_device.c:387 #2: ffff8880186d4da0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff8880186d4da0 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x276/0xad0 net/hsr/hsr_device.c:310 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_forward_skb+0xae/0x2400 net/hsr/hsr_forward.c:614 #4: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #4: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #4: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #5: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44 #6: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #6: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #6: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 stack backtrace: CPU: 1 PID: 5075 Comm: syz-fuzzer Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x13e/0x1d0 net/hsr/hsr_device.c:229 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26c/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] br_dev_queue_push_xmit+0x701/0x8d0 net/bridge/br_forward.c:53 NF_HOOK+0x3a9/0x460 include/linux/netfilter.h:314 br_forward_finish+0xe5/0x140 net/bridge/br_forward.c:66 NF_HOOK+0x3a9/0x460 include/linux/netfilter.h:314 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x660 net/bridge/br_forward.c:236 br_dev_xmit+0x118c/0x1a10 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26c/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] hsr_xmit net/hsr/hsr_forward.c:380 [inline] hsr_forward_do net/hsr/hsr_forward.c:471 [inline] hsr_forward_skb+0x183f/0x2400 net/hsr/hsr_forward.c:619 send_hsr_supervision_frame+0x548/0xad0 net/hsr/hsr_device.c:333 hsr_announce+0x1ab/0x370 net/hsr/hsr_device.c:389 call_timer_fn+0x180/0x600 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers kernel/time/timer.c:2408 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2419 run_timer_base kernel/time/timer.c:2428 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2438 __do_softirq+0x2be/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 4e 39 79 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 f3 e0 e5 f5 65 8b 05 44 c5 84 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc90004227980 EFLAGS: 00000206 RAX: 5e505db5e5c7bc00 RBX: 1ffff92000844f34 RCX: ffffffff944dd603 RDX: dffffc0000000000 RSI: ffffffff8baac1e0 RDI: 0000000000000001 RBP: ffffc90004227a10 R08: ffffffff8f873a6f R09: 1ffffffff1f0e74d R10: dffffc0000000000 R11: fffffbfff1f0e74e R12: dffffc0000000000 R13: 1ffff92000844f30 R14: ffffc900042279a0 R15: 0000000000000246 hrtimer_start_expires include/linux/hrtimer.h:289 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1972 [inline] schedule_hrtimeout_range_clock+0x277/0x480 kernel/time/hrtimer.c:2309 ep_poll fs/eventpoll.c:2026 [inline] do_epoll_wait+0x1cb6/0x1f70 fs/eventpoll.c:2428 do_epoll_pwait+0x56/0x1e0 fs/eventpoll.c:2462 __do_sys_epoll_pwait fs/eventpoll.c:2475 [inline] __se_sys_epoll_pwait fs/eventpoll.c:2469 [inline] __x64_sys_epoll_pwait+0x2b8/0x310 fs/eventpoll.c:2469 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x40720e Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48 RSP: 002b:000000c000951748 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000040720e RDX: 0000000000000080 RSI: 000000c000951818 RDI: 0000000000000004 RBP: 000000c000951790 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000608b R11: 0000000000000246 R12: 000000c000951820 R13: 0000000000000093 R14: 000000c000288680 R15: 0000000000000021 cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: Stall on int endpoint cdc_wdm 4-1:1.0: Cannot schedule work cdc_wdm 4-1:1.0: wdm_int_callback - usb_submit_urb failed with result -1 TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. Sending cookies. ---------------- Code disassembly (best guess): 0: 9c pushf 1: 8f 44 24 20 pop 0x20(%rsp) 5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 4e 39 79 f6 call 0xf6793962 14: f6 44 24 21 02 testb $0x2,0x21(%rsp) 19: 75 52 jne 0x6d 1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 f3 e0 e5 f5 call 0xf5e5e122 <-- trapping instruction 2f: 65 8b 05 44 c5 84 74 mov %gs:0x7484c544(%rip),%eax # 0x7484c57a 36: 85 c0 test %eax,%eax 38: 74 43 je 0x7d 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss