============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.4.931/9861 is trying to acquire lock:
ffff8880340b0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
ffff8880340b0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
but task is already holding lock:
ffff88802ccb0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
ffff88802ccb0fb0 (&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
11 locks held by syz.4.931/9861:
#0: ffff8880250bbfa0 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#0: ffff8880250bbfa0 (sk_lock-AF_INET){+.+.}-{0:0}, at: sk_wait_data+0x2fd/0x4d0 net/core/sock.c:3267
#1: ffff888064eb9bb8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:611 [inline]
#1: ffff888064eb9bb8 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline]
#1: ffff888064eb9bb8 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x36/0x340 mm/mmap_lock.c:501
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
#2: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495
#3: ffffc90000007cc0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745
#4: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#4: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419
#5: ffff88802ccb0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline]
#5: ffff88802ccb0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330
#6: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#6: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#6: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xbb/0x2a80 net/hsr/hsr_forward.c:738
#7: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#7: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#7: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#8: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#8: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#8: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1990 net/bridge/br_device.c:52
#9: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#9: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline]
#9: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791
#10: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#10: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#10: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
stack backtrace:
CPU: 0 UID: 0 PID: 9861 Comm: syz.4.931 Not tainted syzkaller #0 PREEMPT(full)
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:5343 [inline]
netdev_start_xmit include/linux/netdevice.h:5352 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870
dev_queue_xmit include/linux/netdevice.h:3401 [inline]
br_dev_queue_push_xmit+0x370/0x4b0 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/0x1990 net/bridge/br_device.c:108
__netdev_start_xmit include/linux/netdevice.h:5343 [inline]
netdev_start_xmit include/linux/netdevice.h:5352 [inline]
xmit_one net/core/dev.c:3888 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
__dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870
dev_queue_xmit include/linux/netdevice.h:3401 [inline]
hsr_xmit net/hsr/hsr_forward.c:440 [inline]
hsr_forward_do net/hsr/hsr_forward.c:581 [inline]
hsr_forward_skb+0x167e/0x2a80 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:debug_lockdep_rcu_enabled+0xd/0x40 kernel/rcu/update.c:320
Code: 8d 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 13 fc 7e 04 00 <74> 1d 83 3d da 2d 7f 04 00 74 14 65 48 8b 0d 48 95 8a 07 31 c0 83
RSP: 0018:ffffc90003496a10 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff90d2e901 RCX: ffffc90003497428
RDX: ffffc90003496b01 RSI: dffffc0000000000 RDI: ffffc90003496af0
RBP: dffffc0000000000 R08: ffffc90003497410 R09: 0000000000000000
R10: ffffc90003496b38 R11: fffff52000692d69 R12: ffffc90003497420
R13: ffffc90003490000 R14: ffffc90003496ae8 R15: ffffffff81766536
rcu_read_unlock include/linux/rcupdate.h:867 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x1b6d/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2490
folio_alloc_mpol_noprof mm/mempolicy.c:2509 [inline]
vma_alloc_folio_noprof+0xea/0x210 mm/mempolicy.c:2544
folio_prealloc mm/memory.c:-1 [inline]
wp_page_copy mm/memory.c:3780 [inline]
do_wp_page+0x1204/0x5a00 mm/memory.c:4241
handle_pte_fault mm/memory.c:6333 [inline]
__handle_mm_fault mm/memory.c:6455 [inline]
handle_mm_fault+0x1520/0x3310 mm/memory.c:6624
do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0018:ffffc900034977f8 EFLAGS: 00050202
RAX: ffffffff84ad5501 RBX: ffff888034078028 RCX: 0000000000003d38
RDX: 0000000000000000 RSI: ffff88803407c2c8 RDI: 00002000000a4000
RBP: ffffc90003497970 R08: ffff88803407ffff R09: 1ffff1100680ffff
R10: dffffc0000000000 R11: ffffed1006810000 R12: 1ffff92000692fb7
R13: 000020000009fd60 R14: ffffc90003497dc8 R15: 0000000000007fd8
copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
copy_to_user_iter lib/iov_iter.c:25 [inline]
iterate_ubuf include/linux/iov_iter.h:30 [inline]
iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
iterate_and_advance include/linux/iov_iter.h:330 [inline]
_copy_to_iter+0x255/0x17d0 lib/iov_iter.c:197
copy_to_iter include/linux/uio.h:220 [inline]
simple_copy_to_iter net/core/datagram.c:521 [inline]
__skb_datagram_iter+0x41a/0x980 net/core/datagram.c:435
skb_copy_datagram_iter+0xb5/0x240 net/core/datagram.c:535
skb_copy_datagram_msg include/linux/skbuff.h:4243 [inline]
__mptcp_recvmsg_mskq net/mptcp/protocol.c:2083 [inline]
mptcp_recvmsg+0x563/0x1380 net/mptcp/protocol.c:2322
sock_recvmsg_nosec net/socket.c:1137 [inline]
sock_recvmsg+0x155/0x1b0 net/socket.c:1159
__sys_recvfrom+0x240/0x3c0 net/socket.c:2315
__do_sys_recvfrom net/socket.c:2330 [inline]
__se_sys_recvfrom net/socket.c:2326 [inline]
__x64_sys_recvfrom+0xde/0x100 net/socket.c:2326
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: 0033:0x7f1f1979c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1f1a5c0028 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: ffffffffffffffda RBX: 00007f1f19a16180 RCX: 00007f1f1979c819
RDX: fffffffffffffeeb RSI: 0000200000000080 RDI: 0000000000000006
RBP: 00007f1f19832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000101 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1f19a16218 R14: 00007f1f19a16180 R15: 00007ffd6ffe4f18
lec0: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 5400 ms
lec:lec_tx_timeout: lec0
lec:lec_start_xmit: lec0:No lecd attached
lec0: NETDEV WATCHDOG: CPU: 0: transmit queue 0 timed out 5750 ms
lec:lec_tx_timeout: lec0
lec:lec_start_xmit: lec0:No lecd attached
----------------
Code disassembly (best guess):
0: 8d 67 48 lea 0x48(%rdi),%esp
3: 0f b9 3a ud1 (%rdx),%edi
6: 90 nop
7: eb ca jmp 0xffffffd3
9: cc int3
a: cc int3
b: cc int3
c: cc int3
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
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: f3 0f 1e fa endbr64
21: 31 c0 xor %eax,%eax
23: 83 3d 13 fc 7e 04 00 cmpl $0x0,0x47efc13(%rip) # 0x47efc3d
* 2a: 74 1d je 0x49 <-- trapping instruction
2c: 83 3d da 2d 7f 04 00 cmpl $0x0,0x47f2dda(%rip) # 0x47f2e0d
33: 74 14 je 0x49
35: 65 48 8b 0d 48 95 8a mov %gs:0x78a9548(%rip),%rcx # 0x78a9585
3c: 07
3d: 31 c0 xor %eax,%eax
3f: 83 .byte 0x83