============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
sed/24003 is trying to acquire lock:
ffff8880341a6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff8880341a6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
but task is already holding lock:
ffff8880341a6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff8880341a6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_prp_supervision_frame+0x195/0x6c0 net/hsr/hsr_device.c:390
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 sed/24003:
#0: ffff88807e71f180 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:335 [inline]
#0: ffff88807e71f180 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x293/0xb30 mm/mmap.c:1285
#1: ffffc90000007ce0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5a0 kernel/time/timer.c:1745
#2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419
#3: ffff8880341a6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#3: ffff8880341a6f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_prp_supervision_frame+0x195/0x6c0 net/hsr/hsr_device.c:390
#4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb3/0x2880 net/hsr/hsr_forward.c:738
#5: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#5: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4757
#6: ffff888054206228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline]
#6: ffff888054206228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline]
#6: ffff888054206228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4169 [inline]
#6: ffff888054206228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1002/0x3850 net/core/dev.c:4798
#7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:235
#8: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#8: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#8: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1fd/0x14e0 net/ipv6/ndisc.c:482
#9: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#9: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#9: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:235
#10: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#10: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
#10: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4757
#11: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#11: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#11: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
stack backtrace:
CPU: 0 UID: 0 PID: 24003 Comm: sed Not tainted syzkaller #0 PREEMPT(full)
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: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: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
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+0xbaa/0x14e0 net/ipv6/ndisc.c:512
ndisc_send_ns net/ipv6/ndisc.c:670 [inline]
ndisc_solicit+0x374/0x670 net/ipv6/ndisc.c:761
neigh_probe net/core/neighbour.c:1097 [inline]
__neigh_event_send+0xf05/0x14a0 net/core/neighbour.c:1270
neigh_event_send_probe include/net/neighbour.h:480 [inline]
neigh_event_send include/net/neighbour.h:486 [inline]
neigh_resolve_output+0x198/0x750 net/core/neighbour.c:1578
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
ip6tunnel_xmit+0x1c5/0x3e0 include/net/ip6_tunnel.h:162
ip6_tnl_xmit+0x24e1/0x2da0 net/ipv6/ip6_tunnel.c:1280
__gre6_xmit+0xa4d/0xd50 net/ipv6/ip6_gre.c:786
ip6gre_xmit_other net/ipv6/ip6_gre.c:872 [inline]
ip6gre_tunnel_xmit+0xbc9/0x11d0 net/ipv6/ip6_gre.c:899
__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
sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347
__dev_xmit_skb net/core/dev.c:4182 [inline]
__dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4798
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_prp_supervision_frame+0x35b/0x6c0 net/hsr/hsr_device.c:405
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:unwind_next_frame+0x5/0x23c0 arch/x86/kernel/unwind_orc.c:485
Code: e1 07 80 c1 03 38 c1 7c 92 48 89 df e8 84 32 b7 00 eb 88 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <41> 57 41 56 41 55 41 54 53 48 81 ec 98 00 00 00 49 89 fe 48 bd 00
RSP: 0018:ffffc90011a07658 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90011a07720 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff813383b0 RDI: ffffc90011a07668
RBP: ffffc90011a076f0 R08: ffffc90011a07730 R09: 000000000000000a
R10: ffffc90011a076b8 R11: ffffffff81afb170 R12: ffff88807ba88000
R13: 0000000000000020 R14: ffffffff81afb170 R15: ffffc90011a07668
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
slab_free_hook mm/slub.c:2492 [inline]
slab_free mm/slub.c:6674 [inline]
kmem_cache_free+0x169/0x610 mm/slub.c:6785
exit_mmap+0x544/0xb30 mm/mmap.c:1302
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x168/0x220 kernel/exit.c:581
do_exit+0x62e/0x2310 kernel/exit.c:959
do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcd1a9c96c5
Code: Unable to access opcode bytes at 0x7fcd1a9c969b.
RSP: 002b:00007ffff45936a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fcd1aacafe8 RCX: 00007fcd1a9c96c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcd1aac9680 R15: 00007fcd1aacb000
----------------
Code disassembly (best guess):
0: e1 07 loope 0x9
2: 80 c1 03 add $0x3,%cl
5: 38 c1 cmp %al,%cl
7: 7c 92 jl 0xffffff9b
9: 48 89 df mov %rbx,%rdi
c: e8 84 32 b7 00 call 0xb73295
11: eb 88 jmp 0xffffff9b
13: 66 90 xchg %ax,%ax
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: 90 nop
23: 90 nop
24: 90 nop
25: f3 0f 1e fa endbr64
29: 55 push %rbp
* 2a: 41 57 push %r15 <-- trapping instruction
2c: 41 56 push %r14
2e: 41 55 push %r13
30: 41 54 push %r12
32: 53 push %rbx
33: 48 81 ec 98 00 00 00 sub $0x98,%rsp
3a: 49 89 fe mov %rdi,%r14
3d: 48 rex.W
3e: bd .byte 0xbd