============================================
WARNING: possible recursive locking detected
6.16.0-rc3-syzkaller-00837-g28aa52b6189f #0 Not tainted
--------------------------------------------
kworker/u8:13/8346 is trying to acquire lock:
ffff88801a552f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88801a552f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234
but task is already holding lock:
ffff888030d84f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888030d84f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234
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 kworker/u8:13/8346:
#0: ffff88801b2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b2fe148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc900057efbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900057efbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffffffff8f505dd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
#3: ffff88801b2ff188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1712
#4: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#4: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#4: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
#4: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: kernfs_root+0x1c/0x230 fs/kernfs/kernfs-internal.h:75
#5: ffffc90000a08be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0 kernel/time/timer.c:1744
#6: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#6: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#6: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x208/0x1400 net/ipv6/ndisc.c:484
#7: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#7: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#7: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x16a0 net/ipv6/ip6_output.c:126
#8: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#8: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
#8: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70 net/core/dev.c:4636
#9: ffff888030d84f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#9: ffff888030d84f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234
#10: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#10: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#10: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0x9e/0x2860 net/hsr/hsr_forward.c:728
#11: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#11: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
#11: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70 net/core/dev.c:4636
#12: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#12: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#12: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x185/0x1840 net/bridge/br_device.c:52
#13: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#13: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
#13: ffffffff8e13eec0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70 net/core/dev.c:4636
stack backtrace:
CPU: 1 UID: 0 PID: 8346 Comm: kworker/u8:13 Not tainted 6.16.0-rc3-syzkaller-00837-g28aa52b6189f #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3044
check_deadlock kernel/locking/lockdep.c:3096 [inline]
validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3898
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
__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+0x19a/0x220 net/hsr/hsr_device.c:234
__netdev_start_xmit include/linux/netdevice.h:5224 [inline]
netdev_start_xmit include/linux/netdevice.h:5233 [inline]
xmit_one net/core/dev.c:3828 [inline]
dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3844
__dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4711
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:317
br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
NF_HOOK+0x320/0x3c0 include/linux/netfilter.h:317
__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:190
br_flood+0x31a/0x6a0 net/bridge/br_forward.c:237
br_dev_xmit+0x11b3/0x1840 net/bridge/br_device.c:108
__netdev_start_xmit include/linux/netdevice.h:5224 [inline]
netdev_start_xmit include/linux/netdevice.h:5233 [inline]
xmit_one net/core/dev.c:3828 [inline]
dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3844
__dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4711
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+0x1a5/0x220 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5224 [inline]
netdev_start_xmit include/linux/netdevice.h:5233 [inline]
xmit_one net/core/dev.c:3828 [inline]
dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3844
__dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4711
neigh_output include/net/neighbour.h:540 [inline]
ip6_finish_output2+0x11fe/0x16a0 net/ipv6/ip6_output.c:141
__ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:226
NF_HOOK include/linux/netfilter.h:317 [inline]
ndisc_send_skb+0xb47/0x1400 net/ipv6/ndisc.c:513
addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4041
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:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 3b 5d ff 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900057ef5c8 EFLAGS: 00000206
RAX: bf7df2ae3ca3f100 RBX: 0000000000000000 RCX: bf7df2ae3ca3f100
RDX: 0000000000000000 RSI: ffffffff8db73002 RDI: ffffffff8be28d40
RBP: ffffffff825d7d0c R08: 0000000000000000 R09: ffffffff825d7d0c
R10: dffffc0000000000 R11: ffffed10069bf097 R12: 0000000000000002
R13: ffffffff8e13ee60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75
kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
kernfs_parent+0x51/0x190 fs/kernfs/kernfs-internal.h:133
__kernfs_remove+0x93/0x570 fs/kernfs/dir.c:1483
kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1717
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files fs/sysfs/group.c:28 [inline]
sysfs_remove_group+0xfc/0x2c0 fs/sysfs/group.c:322
sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:346
destroy_gid_attrs drivers/infiniband/core/sysfs.c:1182 [inline]
ib_free_port_attrs+0xc5/0x3b0 drivers/infiniband/core/sysfs.c:1407
remove_one_compat_dev drivers/infiniband/core/device.c:1001 [inline]
rdma_dev_exit_net+0x1d8/0x340 drivers/infiniband/core/device.c:1139
ops_exit_list net/core/net_namespace.c:200 [inline]
ops_undo_list+0x497/0x990 net/core/net_namespace.c:253
cleanup_net+0x4c5/0x800 net/core/net_namespace.c:686
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 9c pushf
5: 8f 44 24 30 pop 0x30(%rsp)
9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp)
10: 00
11: 0f 85 cd 00 00 00 jne 0xe4
17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp)
1e: 00
1f: 74 01 je 0x22
21: fb sti
22: 65 48 8b 05 3b 5d ff mov %gs:0x10ff5d3b(%rip),%rax # 0x10ff5d65
29: 10
* 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction
2f: 0f 85 f2 00 00 00 jne 0x127
35: 48 83 c4 60 add $0x60,%rsp
39: 5b pop %rbx
3a: 41 5c pop %r12
3c: 41 5d pop %r13
3e: 41 5e pop %r14