============================================
WARNING: possible recursive locking detected
syzkaller #0 Tainted: G L
--------------------------------------------
dhcpcd-run-hook/12926 is trying to acquire lock:
ffff888029ee4fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
ffff888029ee4fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
but task is already holding lock:
ffff88805d518fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
ffff88805d518fb0 (&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
9 locks held by dhcpcd-run-hook/12926:
#0: ffff888033bf8338 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#0: ffff888033bf8338 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x234/0x4f0 mm/util.c:579
#1: ffffc90000a08cc0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745
#2: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:847 [inline]
#2: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419
#3: ffff88805d518fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
#3: ffff88805d518fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330
#4: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#4: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:847 [inline]
#4: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb3/0x2860 net/hsr/hsr_forward.c:738
#5: ffffffff8e75d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#5: ffffffff8e75d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:900 [inline]
#5: ffffffff8e75d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x277/0x3860 net/core/dev.c:4778
#6: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#6: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:847 [inline]
#6: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1980 net/bridge/br_device.c:52
#7: ffffffff8e75d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8e75d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:900 [inline]
#7: ffffffff8e75d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x277/0x3860 net/core/dev.c:4778
#8: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#8: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:847 [inline]
#8: ffffffff8e75d020 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
stack backtrace:
CPU: 1 UID: 0 PID: 12926 Comm: dhcpcd-run-hook Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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+0x106/0x350 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:182
spin_lock_bh include/linux/spinlock.h:348 [inline]
hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5325 [inline]
netdev_start_xmit include/linux/netdevice.h:5334 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x16d1/0x3860 net/core/dev.c:4854
dev_queue_xmit include/linux/netdevice.h:3385 [inline]
br_dev_queue_push_xmit+0x370/0x4a0 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+0x12bd/0x1980 net/bridge/br_device.c:108
__netdev_start_xmit include/linux/netdevice.h:5325 [inline]
netdev_start_xmit include/linux/netdevice.h:5334 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x16d1/0x3860 net/core/dev.c:4854
dev_queue_xmit include/linux/netdevice.h:3385 [inline]
hsr_xmit net/hsr/hsr_forward.c:440 [inline]
hsr_forward_do net/hsr/hsr_forward.c:581 [inline]
hsr_forward_skb+0x157b/0x2860 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+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320
Code: 11 10 48 89 74 11 18 48 89 44 11 20 e9 d4 df 4a ff cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d a8 fe 56 11 65 8b 15 c9 fe 56
RSP: 0018:ffffc90000a672b8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000006 RCX: 0000000000000003
RDX: 0000000000000001 RSI: 0000000000000006 RDI: 0000000000000006
RBP: ffffc90000a674b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff34feeac R12: ffff8880795cf416
R13: dffffc0000000000 R14: 0000000000000002 R15: 000000000000000e
mas_parent_type lib/maple_tree.c:476 [inline]
mas_validate_parent_slot lib/maple_tree.c:6974 [inline]
mt_validate+0x590/0x4320 lib/maple_tree.c:7172
validate_mm+0xd4/0x4c0 mm/vma.c:649
mmap_region+0x1559/0x22a0 mm/vma.c:2850
do_mmap+0xc39/0x10c0 mm/mmap.c:559
vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
ksys_mmap_pgoff+0x51e/0x760 mm/mmap.c:605
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1f3688242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffceea00b28 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fa1f335c000 RCX: 00007fa1f3688242
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007fa1f335c000
RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000006000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffceea00be8
R13: 00007fa1f335f0c0 R14: 00007ffceea00f60 R15: 00000fff9dd40168
----------------
Code disassembly (best guess):
0: 11 10 adc %edx,(%rax)
2: 48 89 74 11 18 mov %rsi,0x18(%rcx,%rdx,1)
7: 48 89 44 11 20 mov %rax,0x20(%rcx,%rdx,1)
c: e9 d4 df 4a ff jmp 0xff4adfe5
11: cc int3
12: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
19: 00
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: 90 nop
26: 90 nop
27: 90 nop
28: 90 nop
29: 90 nop
* 2a: f3 0f 1e fa endbr64 <-- trapping instruction
2e: 48 8b 04 24 mov (%rsp),%rax
32: 65 48 8b 0d a8 fe 56 mov %gs:0x1156fea8(%rip),%rcx # 0x1156fee2
39: 11
3a: 65 gs
3b: 8b .byte 0x8b
3c: 15 .byte 0x15
3d: c9 leave
3e: fe (bad)
3f: 56 push %rsi