============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz-executor/15338 is trying to acquire lock:
ffff88805849cd80 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88805849cd80 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0x1dc/0x350 net/hsr/hsr_device.c:237
but task is already holding lock:
ffff88803041ad80 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88803041ad80 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x311/0xb90 net/hsr/hsr_device.c:323
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/15338:
#0: ffff888068d56418 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
#1: ffff88807e439de8 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
#1: ffff88807e439de8 (&type->i_mutex_dir_key#5/1){+.+.}-{3:3}, at: do_rmdir+0x1c6/0x590 fs/namei.c:4251
#2: ffff88807b18b8c8 (&type->i_mutex_dir_key#5){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#2: ffff88807b18b8c8 (&type->i_mutex_dir_key#5){++++}-{3:3}, at: vfs_rmdir+0xf2/0x4d0 fs/namei.c:4193
#3: ffff88807e439c48 (&simple_offset_xa_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#3: ffff88807e439c48 (&simple_offset_xa_lock){+.+.}-{2:2}, at: xa_erase+0x32/0x100 lib/xarray.c:1515
#4: ffffc900001f0c00 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd2/0x540 kernel/time/timer.c:1698
#5: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#5: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#5: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: hsr_announce+0x84/0x350 net/hsr/hsr_device.c:400
#6: ffff88803041ad80 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#6: ffff88803041ad80 (&hsr->seqnr_lock){+.-.}-{2:2}, at: send_hsr_supervision_frame+0x311/0xb90 net/hsr/hsr_device.c:323
#7: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#7: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#7: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: hsr_forward_skb+0xa5/0x2140 net/hsr/hsr_forward.c:621
#8: ffffffff8d132000 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#8: ffffffff8d132000 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:838 [inline]
#8: ffffffff8d132000 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x26b/0x36b0 net/core/dev.c:4363
#9: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#9: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#9: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x196/0x1900 net/bridge/br_device.c:50
#10: ffffffff8d132000 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#10: ffffffff8d132000 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:838 [inline]
#10: ffffffff8d132000 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x26b/0x36b0 net/core/dev.c:4363
#11: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#11: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#11: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: hsr_dev_xmit+0x2d/0x350 net/hsr/hsr_device.c:231
stack backtrace:
CPU: 1 PID: 15338 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
<IRQ>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain kernel/locking/lockdep.c:3856 [inline]
__lock_acquire+0x5dbc/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__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+0x1dc/0x350 net/hsr/hsr_device.c:237
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3632 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3648
__dev_queue_xmit+0x1ac2/0x36b0 net/core/dev.c:4438
dev_queue_xmit include/linux/netdevice.h:3113 [inline]
br_dev_queue_push_xmit+0x6b3/0x870 net/bridge/br_forward.c:53
NF_HOOK+0x351/0x3e0 include/linux/netfilter.h:304
br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
NF_HOOK+0x351/0x3e0 include/linux/netfilter.h:304
__br_forward+0x433/0x610 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver+0xb5/0x150 net/bridge/br_forward.c:191
br_flood+0x31b/0x670 net/bridge/br_forward.c:237
br_dev_xmit+0x127c/0x1900 net/bridge/br_device.c:106
__netdev_start_xmit include/linux/netdevice.h:4943 [inline]
netdev_start_xmit include/linux/netdevice.h:4957 [inline]
xmit_one net/core/dev.c:3632 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3648
__dev_queue_xmit+0x1ac2/0x36b0 net/core/dev.c:4438
dev_queue_xmit include/linux/netdevice.h:3113 [inline]
hsr_xmit net/hsr/hsr_forward.c:382 [inline]
hsr_forward_do net/hsr/hsr_forward.c:473 [inline]
hsr_forward_skb+0x1335/0x2140 net/hsr/hsr_forward.c:626
send_hsr_supervision_frame+0x5fb/0xb90 net/hsr/hsr_device.c:346
hsr_announce+0x198/0x350 net/hsr/hsr_device.c:402
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x4aa/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 29 e0 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4d 8d 3c 44 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 75 3e 4d 63 2f <4d> 01 fd 4c 89 ef 4c 89 f6 e8 48 dc 4b 00 49 8d 47 04 4d 39 f5 4c
RSP: 0018:ffffc900033e7638 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8f031384 RCX: 0000000000000007
RDX: dffffc0000000000 RSI: ffffffff8a774d47 RDI: ffffffff8a774dd7
RBP: ffffffff8f031368 R08: ffffc900033e77d0 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff8f031368
R13: fffffffffb743a57 R14: ffffffff8a774d47 R15: ffffffff8f031374
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
__call_rcu_common kernel/rcu/tree.c:2721 [inline]
call_rcu+0x153/0x950 kernel/rcu/tree.c:2837
xa_node_free lib/xarray.c:258 [inline]
xas_delete_node lib/xarray.c:495 [inline]
update_node lib/xarray.c:759 [inline]
xas_store+0xe39/0x19e0 lib/xarray.c:844
__xa_erase lib/xarray.c:1495 [inline]
xa_erase+0x68/0x100 lib/xarray.c:1516
simple_offset_remove+0x62/0x90 fs/libfs.c:331
shmem_unlink+0x1ad/0x2e0 mm/shmem.c:3357
shmem_rmdir+0x6b/0x80 mm/shmem.c:3375
vfs_rmdir+0x370/0x4d0 fs/namei.c:4204
do_rmdir+0x29f/0x590 fs/namei.c:4263
__do_sys_unlinkat fs/namei.c:4441 [inline]
__se_sys_unlinkat fs/namei.c:4435 [inline]
__x64_sys_unlinkat+0xc4/0xe0 fs/namei.c:4435
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7ae579b8b7
Code: 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 07 01 00 00 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:00007ffcf85dc7c8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f7ae579b8b7
RDX: 0000000000000200 RSI: 00007ffcf85dd910 RDI: 00000000ffffff9c
RBP: 00007f7ae5831f90 R08: 00000000000185e0 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffcf85dd910
R13: 00007f7ae5831f90 R14: 0000000000152056 R15: 00007ffcf85dd950
</TASK>
----------------
Code disassembly (best guess):
0: 29 e0 sub %esp,%eax
2: 48 89 c1 mov %rax,%rcx
5: 48 c1 f9 02 sar $0x2,%rcx
9: 48 c1 e8 3f shr $0x3f,%rax
d: 48 01 c8 add %rcx,%rax
10: 48 83 e0 fe and $0xfffffffffffffffe,%rax
14: 4d 8d 3c 44 lea (%r12,%rax,2),%r15
18: 4c 89 f8 mov %r15,%rax
1b: 48 c1 e8 03 shr $0x3,%rax
1f: 0f b6 04 10 movzbl (%rax,%rdx,1),%eax
23: 84 c0 test %al,%al
25: 75 3e jne 0x65
27: 4d 63 2f movslq (%r15),%r13
* 2a: 4d 01 fd add %r15,%r13 <-- trapping instruction
2d: 4c 89 ef mov %r13,%rdi
30: 4c 89 f6 mov %r14,%rsi
33: e8 48 dc 4b 00 call 0x4bdc80
38: 49 8d 47 04 lea 0x4(%r15),%rax
3c: 4d 39 f5 cmp %r14,%r13
3f: 4c rex.WR