============================================ WARNING: possible recursive locking detected 6.14.0-rc2-syzkaller #0 Not tainted -------------------------------------------- syz-executor/9558 is trying to acquire lock: ffff8880516b8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880516b8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 but task is already holding lock: ffff88805c1f6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88805c1f6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 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 12 locks held by syz-executor/9558: #0: ffff888012330b68 (&vma->vm_lock->lock){++++}-{4:4}, at: vma_start_read include/linux/mm.h:717 [inline] #0: ffff888012330b68 (&vma->vm_lock->lock){++++}-{4:4}, at: lock_vma_under_rcu+0x34b/0x790 mm/memory.c:6367 #1: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x82/0x380 mm/pgtable-generic.c:287 #2: ffff88807e6a1678 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88807e6a1678 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: handle_pte_fault mm/memory.c:5897 [inline] #2: ffff88807e6a1678 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __handle_mm_fault+0x1541/0x70f0 mm/memory.c:6032 #3: ffffc90000007be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1786 #4: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: ip6_nd_hdr net/ipv6/ndisc.c:454 [inline] #4: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x563/0x1450 net/ipv6/ndisc.c:505 #5: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #5: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #5: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x61d/0x1780 net/ipv6/ip6_output.c:126 #6: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #6: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline] #6: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f50 net/core/dev.c:4509 #7: ffff88805c1f6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #7: ffff88805c1f6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 #8: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #8: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #8: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb6/0x2d50 net/hsr/hsr_forward.c:728 #9: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline] #9: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f50 net/core/dev.c:4509 #10: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #10: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #10: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x21d/0x1b40 net/bridge/br_device.c:50 #11: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #11: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline] #11: ffffffff8e938840 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f50 net/core/dev.c:4509 stack backtrace: CPU: 0 UID: 0 PID: 9558 Comm: syz-executor Not tainted 6.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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+0x18a/0x210 net/hsr/hsr_device.c:234 __netdev_start_xmit include/linux/netdevice.h:5144 [inline] netdev_start_xmit include/linux/netdevice.h:5153 [inline] xmit_one net/core/dev.c:3735 [inline] dev_hard_start_xmit+0x27c/0x7d0 net/core/dev.c:3751 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4584 dev_queue_xmit include/linux/netdevice.h:3305 [inline] br_dev_queue_push_xmit+0x726/0x900 net/bridge/br_forward.c:53 NF_HOOK+0x3a9/0x460 include/linux/netfilter.h:314 br_forward_finish+0xd8/0x130 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+0x2e4/0x680 net/bridge/br_forward.c:237 br_dev_xmit+0x1202/0x1b40 __netdev_start_xmit include/linux/netdevice.h:5144 [inline] netdev_start_xmit include/linux/netdevice.h:5153 [inline] xmit_one net/core/dev.c:3735 [inline] dev_hard_start_xmit+0x27c/0x7d0 net/core/dev.c:3751 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4584 dev_queue_xmit include/linux/netdevice.h:3305 [inline] hsr_xmit net/hsr/hsr_forward.c:430 [inline] hsr_forward_do net/hsr/hsr_forward.c:571 [inline] hsr_forward_skb+0x1842/0x2d50 net/hsr/hsr_forward.c:733 hsr_dev_xmit+0x195/0x210 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5144 [inline] netdev_start_xmit include/linux/netdevice.h:5153 [inline] xmit_one net/core/dev.c:3735 [inline] dev_hard_start_xmit+0x27c/0x7d0 net/core/dev.c:3751 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4584 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x12af/0x1780 net/ipv6/ip6_output.c:141 ip6_finish_output+0x41e/0x840 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:314 [inline] ndisc_send_skb+0xb30/0x1450 net/ipv6/ndisc.c:511 addrconf_rs_timer+0x371/0x670 net/ipv6/addrconf.c:4033 call_timer_fn+0x189/0x650 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x90 kernel/kcov.c:321 Code: 44 0a 20 e9 a5 ec 50 ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 <65> 48 8b 0c 25 80 d6 03 00 65 8b 05 f0 81 44 7e 25 00 01 ff 00 74 RSP: 0000:ffffc90004cf77b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff888030793c00 RDX: ffff888030793c00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90004cf79f0 R08: ffffffff820c8f1f R09: fffff5200099ef30 R10: dffffc0000000000 R11: fffff5200099ef30 R12: 0000000008100073 R13: ffffc90004cf7db8 R14: 0000000000000000 R15: 1ffff9200099efb7 userfaultfd_pte_wp include/linux/userfaultfd_k.h:201 [inline] do_wp_page+0x1ef/0x49b0 mm/memory.c:3746 handle_pte_fault mm/memory.c:5905 [inline] __handle_mm_fault+0x24d5/0x70f0 mm/memory.c:6032 handle_mm_fault+0x3e5/0x8d0 mm/memory.c:6201 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fe341b832e7 Code: f7 fb ff 49 39 c4 0f 84 df 02 00 00 4c 89 e7 e8 4f f7 fb ff 8b 00 f6 c4 80 75 d8 4c 89 e7 e8 40 f7 fb ff 48 8b 80 88 00 00 00 <48> c7 00 00 00 00 00 48 c7 40 08 00 00 00 00 eb b8 0f 1f 84 00 00 RSP: 002b:00007fff5553c7a0 EFLAGS: 00010246 RAX: 00007fe3428d8710 RBX: 0000000000000000 RCX: 00007fe341d7cca0 RDX: 0000000000000000 RSI: 00007fe341d7cca0 RDI: 00007fe341d7c620 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055558adc27d0 R11: 0000000000000246 R12: 00007fe341d7c620 R13: 00000000000927c0 R14: 0000000000066366 R15: 00007fff5553c930 ---------------- Code disassembly (best guess): 0: 44 0a 20 or (%rax),%r12b 3: e9 a5 ec 50 ff jmp 0xff50ecad 8: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) f: 00 00 00 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: f3 0f 1e fa endbr64 26: 4c 8b 04 24 mov (%rsp),%r8 * 2a: 65 48 8b 0c 25 80 d6 mov %gs:0x3d680,%rcx <-- trapping instruction 31: 03 00 33: 65 8b 05 f0 81 44 7e mov %gs:0x7e4481f0(%rip),%eax # 0x7e44822a 3a: 25 00 01 ff 00 and $0xff0100,%eax 3f: 74 .byte 0x74