============================================ WARNING: possible recursive locking detected syzkaller #0 Tainted: G L -------------------------------------------- syz.1.4057/22548 is trying to acquire lock: ffff88805f486f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline] ffff88805f486f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 but task is already holding lock: ffff888077ee6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline] ffff888077ee6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330 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 10 locks held by syz.1.4057/22548: #0: ffffffff8ec6a818 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffffffff8ec6a818 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffffffff8ec6a818 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8ec6a818 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_number_perm+0x219/0x630 security/tomoyo/file.c:727 #1: ffffffff8e69ba30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #1: ffffffff8e69ba30 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:294 #2: ffffc90000007ce0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5a0 kernel/time/timer.c:1745 #3: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #3: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #3: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419 #4: ffff888077ee6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline] #4: ffff888077ee6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330 #5: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #5: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #5: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb3/0x2880 net/hsr/hsr_forward.c:738 #6: ffffffff8e55ddc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #6: ffffffff8e55ddc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #6: ffffffff8e55ddc0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4757 #7: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #7: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #7: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1920 net/bridge/br_device.c:52 #8: ffffffff8e55ddc0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e55ddc0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #8: ffffffff8e55ddc0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4757 #9: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #9: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #9: ffffffff8e55dd60 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 stack backtrace: CPU: 0 UID: 0 PID: 22548 Comm: syz.1.4057 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:347 [inline] hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3866 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4832 dev_queue_xmit include/linux/netdevice.h:3381 [inline] br_dev_queue_push_xmit+0x6d2/0x8b0 net/bridge/br_forward.c:53 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_dev_xmit+0x127a/0x1920 net/bridge/br_device.c:108 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3866 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4832 dev_queue_xmit include/linux/netdevice.h:3381 [inline] hsr_xmit net/hsr/hsr_forward.c:440 [inline] hsr_forward_do net/hsr/hsr_forward.c:581 [inline] hsr_forward_skb+0x15a0/0x2880 net/hsr/hsr_forward.c:743 send_hsr_supervision_frame+0x731/0xcb0 net/hsr/hsr_device.c:364 hsr_announce+0x1db/0x370 net/hsr/hsr_device.c:421 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:page_slab mm/slab.h:143 [inline] RIP: 0010:virt_to_slab mm/slab.h:178 [inline] RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline] RIP: 0010:qlist_free_all+0x4a/0x100 mm/kasan/quarantine.c:176 Code: 89 ef 4d 89 f4 4d 85 f6 75 40 4c 8b 25 cf 32 ca 0b 4c 89 ff e8 27 d1 49 ff 48 c1 e8 06 48 83 e0 c0 49 8d 0c 04 49 8b 44 04 08 <48> 89 c2 48 ff ca a8 01 48 0f 44 d1 0f b6 42 33 c1 e0 18 3d 00 00 RSP: 0018:ffffc90005577a68 EFLAGS: 00000202 RAX: ffffea0002348e01 RBX: ffffc90005577aa0 RCX: ffffea0002348e80 RDX: ffffc9001317f000 RSI: 0000000000007e2e RDI: 0000000000007e2f RBP: ffff88808d23a000 R08: 0000000000000000 R09: ffffffff822db2bc R10: dffffc0000000000 R11: fffffbfff1fe024f R12: ffffea0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88808d23a000 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x3c2/0x7e0 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:962 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x246/0x630 security/tomoyo/file.c:728 security_file_ioctl+0xc3/0x2a0 security/security.c:2435 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f729cd9bc0b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007f729afd3450 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f729cd9bc0b RDX: 00007f729afd3bd0 RSI: 000000004020ae46 RDI: 0000000000000004 RBP: 0000000000000004 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 00000000fec00000 R13: 00007f729afd3bd0 R14: 0000200000011000 R15: 0000000000000011 ---------------- Code disassembly (best guess): 0: 89 ef mov %ebp,%edi 2: 4d 89 f4 mov %r14,%r12 5: 4d 85 f6 test %r14,%r14 8: 75 40 jne 0x4a a: 4c 8b 25 cf 32 ca 0b mov 0xbca32cf(%rip),%r12 # 0xbca32e0 11: 4c 89 ff mov %r15,%rdi 14: e8 27 d1 49 ff call 0xff49d140 19: 48 c1 e8 06 shr $0x6,%rax 1d: 48 83 e0 c0 and $0xffffffffffffffc0,%rax 21: 49 8d 0c 04 lea (%r12,%rax,1),%rcx 25: 49 8b 44 04 08 mov 0x8(%r12,%rax,1),%rax * 2a: 48 89 c2 mov %rax,%rdx <-- trapping instruction 2d: 48 ff ca dec %rdx 30: a8 01 test $0x1,%al 32: 48 0f 44 d1 cmove %rcx,%rdx 36: 0f b6 42 33 movzbl 0x33(%rdx),%eax 3a: c1 e0 18 shl $0x18,%eax 3d: 3d .byte 0x3d