============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.2.980/9809 is trying to acquire lock:
ffff8880213aaf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff8880213aaf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
but task is already holding lock:
ffff888078f1cf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888078f1cf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
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
14 locks held by syz.2.980/9809:
#0: ffff888033822ce0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:387 [inline]
#0: ffff888033822ce0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:368 [inline]
#0: ffff888033822ce0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:428
#1: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#1: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x29/0x250 mm/pgtable-generic.c:286
#2: ffff888057bec078 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffff888057bec078 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x13e/0x210 mm/pgtable-generic.c:401
#3: ffffc90000007be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0 kernel/time/timer.c:1744
#4: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#4: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#4: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1e4/0x1510 net/ipv6/ndisc.c:482
#5: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#5: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#5: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:235
#6: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#6: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4688
#7: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#7: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#7: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
#8: ffff888078f1cf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#8: ffff888078f1cf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
#9: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#9: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#9: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0x9e/0x2860 net/hsr/hsr_forward.c:728
#10: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#10: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#10: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4688
#11: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#11: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#11: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x185/0x1840 net/bridge/br_device.c:52
#12: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#12: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#12: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4688
#13: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#13: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#13: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
stack backtrace:
CPU: 0 UID: 0 PID: 9809 Comm: syz.2.980 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041
check_deadlock kernel/locking/lockdep.c:3093 [inline]
validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861
__dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4763
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
br_dev_queue_push_xmit+0x6c5/0x890 net/bridge/br_forward.c:53
NF_HOOK+0x320/0x3c0 include/linux/netfilter.h:318
br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
NF_HOOK+0x320/0x3c0 include/linux/netfilter.h:318
__br_forward+0x41e/0x600 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver+0xb5/0x160 net/bridge/br_forward.c:191
br_flood+0x31a/0x6a0 net/bridge/br_forward.c:238
br_dev_xmit+0x11b3/0x1840 net/bridge/br_device.c:108
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861
__dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4763
dev_queue_xmit include/linux/netdevice.h:3365 [inline]
hsr_xmit net/hsr/hsr_forward.c:430 [inline]
hsr_forward_do net/hsr/hsr_forward.c:571 [inline]
hsr_forward_skb+0x158b/0x2860 net/hsr/hsr_forward.c:733
hsr_dev_xmit+0x242/0x360 net/hsr/hsr_device.c:236
__netdev_start_xmit include/linux/netdevice.h:5248 [inline]
netdev_start_xmit include/linux/netdevice.h:5257 [inline]
xmit_one net/core/dev.c:3845 [inline]
dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861
__dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4763
neigh_output include/net/neighbour.h:547 [inline]
ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK include/linux/netfilter.h:318 [inline]
ndisc_send_skb+0xbce/0x1510 net/ipv6/ndisc.c:512
addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4037
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x286/0x870 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd3c/0x12d0 kernel/smp.c:877
Code: 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 42 0f b6 04 2b 84 c0 75 11 <41> f7 04 24 01 00 00 00 74 1e e8 45 6f 0b 00 eb e4 44 89 e1 80 e1
RSP: 0018:ffffc90003aaefc0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff11017127ffd RCX: 0000000000080000
RDX: ffffc9000e111000 RSI: 000000000004a8f1 RDI: 000000000004a8f2
RBP: ffffc90003aaf140 R08: ffffffff8f7ce277 R09: 1ffffffff1ef9c4e
R10: dffffc0000000000 R11: fffffbfff1ef9c4f R12: ffff8880b893ffe8
R13: dffffc0000000000 R14: ffff8880b883b240 R15: 0000000000000001
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline]
flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1471
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101
wp_page_copy mm/memory.c:3745 [inline]
do_wp_page+0x1bc2/0x5800 mm/memory.c:4140
handle_pte_fault mm/memory.c:6193 [inline]
__handle_mm_fault+0x1033/0x5400 mm/memory.c:6318
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 07 68 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003aaf8b8 EFLAGS: 00050202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000021030
RDX: ffff888031a63c80 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90003aafa30 R08: ffffc90003aaf667 R09: 1ffff92000755ecc
R10: dffffc0000000000 R11: fffff52000755ecd R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000200000021000
____sys_recvmsg+0x2ab/0x460 net/socket.c:2863
___sys_recvmsg+0x1b5/0x510 net/socket.c:2892
do_recvmmsg+0x307/0x770 net/socket.c:2987
__sys_recvmmsg net/socket.c:3061 [inline]
__do_sys_recvmmsg net/socket.c:3084 [inline]
__se_sys_recvmmsg net/socket.c:3077 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3077
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f109438f6c9
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:00007f109519f038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f10945e6090 RCX: 00007f109438f6c9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f1094411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f10945e6128 R14: 00007f10945e6090 R15: 00007f109470fa28
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 31 ff xor %edi,%edi
2: e8 b6 73 0b 00 call 0xb73bd
7: 41 83 e5 01 and $0x1,%r13d
b: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
12: fc ff df
15: 75 07 jne 0x1e
17: e8 61 6f 0b 00 call 0xb6f7d
1c: eb 38 jmp 0x56
1e: f3 90 pause
20: 42 0f b6 04 2b movzbl (%rbx,%r13,1),%eax
25: 84 c0 test %al,%al
27: 75 11 jne 0x3a
* 29: 41 f7 04 24 01 00 00 testl $0x1,(%r12) <-- trapping instruction
30: 00
31: 74 1e je 0x51
33: e8 45 6f 0b 00 call 0xb6f7d
38: eb e4 jmp 0x1e
3a: 44 89 e1 mov %r12d,%ecx
3d: 80 .byte 0x80
3e: e1 .byte 0xe1