============================================ WARNING: possible recursive locking detected 6.1.92-syzkaller #0 Not tainted -------------------------------------------- syz-executor.2/10644 is trying to acquire lock: ffff0000ed7c8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff0000ed7c8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0xf8/0x2d8 net/hsr/hsr_device.c:219 but task is already holding lock: ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x1fc/0x8a4 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 8 locks held by syz-executor.2/10644: #0: ffff0000e795b590 (&u->iolock){+.+.}-{3:3}, at: __unix_dgram_recvmsg+0x1ec/0xe2c net/unix/af_unix.c:2443 #1: ffff800008007c80 ((&hsr->announce_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline] #1: ffff800008007c80 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd0/0xa1c kernel/time/timer.c:1494 #2: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 #3: ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff0000f14d0d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x1fc/0x8a4 net/hsr/hsr_device.c:300 #4: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 #5: ffff800015a24d00 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:349 #6: ffff800015a24ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 #7: ffff800015a24d00 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:349 stack backtrace: CPU: 0 PID: 10644 Comm: syz-executor.2 Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 __lock_acquire+0x6310/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x54/0x6c kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0xf8/0x2d8 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+0x25c/0x9a4 net/core/dev.c:3643 __dev_queue_xmit+0x186c/0x38d8 net/core/dev.c:4293 dev_queue_xmit include/linux/netdevice.h:3021 [inline] br_dev_queue_push_xmit+0x584/0x730 net/bridge/br_forward.c:53 NF_HOOK+0x35c/0x408 include/linux/netfilter.h:302 br_forward_finish+0xd0/0x118 net/bridge/br_forward.c:66 NF_HOOK+0x35c/0x408 include/linux/netfilter.h:302 __br_forward+0x2f0/0x458 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xc8/0x178 net/bridge/br_forward.c:189 br_flood+0x28c/0x3f8 net/bridge/br_forward.c:231 br_dev_xmit+0xd88/0x137c __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+0x25c/0x9a4 net/core/dev.c:3643 __dev_queue_xmit+0x186c/0x38d8 net/core/dev.c:4293 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+0x1048/0x1c5c net/hsr/hsr_forward.c:619 send_hsr_supervision_frame+0x414/0x8a4 net/hsr/hsr_device.c:323 hsr_announce+0x17c/0x31c net/hsr/hsr_device.c:379 call_timer_fn+0x1c0/0xa1c kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x554/0x718 kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 __do_softirq+0x314/0xe38 kernel/softirq.c:571 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x264/0x4d4 kernel/softirq.c:650 irq_exit_rcu+0x14/0x84 kernel/softirq.c:662 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock_irqrestore+0x58/0xac kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __skb_try_recv_datagram+0x198/0x584 net/core/datagram.c:265 __unix_dgram_recvmsg+0x2f8/0xe2c net/unix/af_unix.c:2446 unix_dgram_recvmsg+0xd0/0xe8 net/unix/af_unix.c:2543 ____sys_recvmsg+0x234/0x69c ___sys_recvmsg net/socket.c:2775 [inline] do_recvmmsg+0x41c/0xb60 net/socket.c:2869 __sys_recvmmsg net/socket.c:2948 [inline] __do_sys_recvmmsg net/socket.c:2971 [inline] __se_sys_recvmmsg net/socket.c:2964 [inline] __arm64_sys_recvmmsg+0x180/0x23c net/socket.c:2964 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585