============================================
WARNING: possible recursive locking detected
6.16.0-rc4-syzkaller-00993-g59f44c9ccc3b #0 Not tainted
--------------------------------------------
kworker/u8:6/3475 is trying to acquire lock:
ffff888034d84f30 (&hsr->seqnr_lock){+.-.}-{3:3}
, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234
but task is already holding lock:
ffff88803191af30 (
&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
&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
16 locks held by kworker/u8:6/3475:
#0: ffff888140aa5148
((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
#1: ffffc9000bcf7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000bcf7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
#2: ffff88803204e0e0 (&type->s_umount_key#31){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff888035058b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
#3: ffff888035058b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1804 [inline]
#3: ffff888035058b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:2952
#4: ffff88803505a950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f87/0x21c0 fs/jbd2/transaction.c:444
#5: ffff8880505e0270 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x83b/0x18d0 fs/ext4/inode.c:812
#6: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#6: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#6: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
#6: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
#7: ffffc90000007be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0 kernel/time/timer.c:1744
#8: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#8: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#8: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x20c/0x1440 net/ipv6/ndisc.c:485
#9: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#9: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#9: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x16a0 net/ipv6/ip6_output.c:126
#10: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#10: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
#10: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70 net/core/dev.c:4636
#11: ffff88803191af30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#11: ffff88803191af30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234
#12: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#12: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#12: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0x9e/0x2860 net/hsr/hsr_forward.c:728
#13: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#13: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
#13: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70 net/core/dev.c:4636
#14: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#14: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#14: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x185/0x1840 net/bridge/br_device.c:52
#15: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#15: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
#15: ffffffff8e13ee80 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27e/0x3a70 net/core/dev.c:4636
stack backtrace:
CPU: 0 UID: 0 PID: 3475 Comm: kworker/u8:6 Not tainted 6.16.0-rc4-syzkaller-00993-g59f44c9ccc3b #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-8:0)
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:5217 [inline]
netdev_start_xmit include/linux/netdevice.h:5226 [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:3358 [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:5217 [inline]
netdev_start_xmit include/linux/netdevice.h:5226 [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:3358 [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:5217 [inline]
netdev_start_xmit include/linux/netdevice.h:5226 [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:542 [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+0xb54/0x1440 net/ipv6/ndisc.c:515
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 0b 6d 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000bcf60b8 EFLAGS: 00000206
RAX: 8a84fcaac775cb00 RBX: 0000000000000000 RCX: 8a84fcaac775cb00
RDX: 0000000000000000 RSI: ffffffff8db89bbe RDI: ffffffff8be28f80
RBP: ffffffff81729af5 R08: 0000000000000000 R09: ffffffff81729af5
R10: ffffc9000bcf6278 R11: ffffffff81acf6d0 R12: 0000000000000002
R13: ffffffff8e13ee20 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]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4148 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
ext4_mb_new_blocks+0x559/0x46a0 fs/ext4/mballoc.c:6195
ext4_ext_map_blocks+0x161a/0x6ac0 fs/ext4/extents.c:4383
ext4_map_create_blocks fs/ext4/inode.c:609 [inline]
ext4_map_blocks+0x931/0x18d0 fs/ext4/inode.c:813
mpage_map_one_extent fs/ext4/inode.c:2348 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2401 [inline]
ext4_do_writepages+0x212f/0x3f30 fs/ext4/inode.c:2863
ext4_writepages+0x205/0x350 fs/ext4/inode.c:2953
do_writepages+0x32e/0x550 mm/page-writeback.c:2636
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xade/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 0b 6d 02 mov %gs:0x11026d0b(%rip),%rax # 0x11026d35
29: 11
* 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