======================================================
WARNING: possible circular locking dependency detected
5.18.0-rc4-next-20220429-syzkaller #0 Not tainted
------------------------------------------------------
kworker/1:1/27 is trying to acquire lock:
ffff8881483680d0 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:379 [inline]
ffff8881483680d0 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0xf7/0x1690 block/blk-throttle.c:1152
but task is already holding lock:
ffffc900001f0d70 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline]
ffffc900001f0d70 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1434
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 ((&sq->pending_timer)){+.-.}-{0:0}:
del_timer_sync+0x5b/0x1b0 kernel/time/timer.c:1387
throtl_pd_free+0x15/0x40 block/blk-throttle.c:500
blkcg_deactivate_policy block/blk-cgroup.c:1445 [inline]
blkcg_deactivate_policy+0x2d2/0x4e0 block/blk-cgroup.c:1423
blk_throtl_exit+0x8a/0x1a0 block/blk-throttle.c:2335
blkcg_init_queue+0x225/0x810 block/blk-cgroup.c:1226
__alloc_disk_node+0x260/0x610 block/genhd.c:1381
__blk_mq_alloc_disk+0x133/0x1c0 block/blk-mq.c:3931
nbd_dev_add+0x3b2/0xcd0 drivers/block/nbd.c:1762
nbd_genl_connect+0x11f3/0x1930 drivers/block/nbd.c:1945
genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:731
genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:792
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:725
____sys_sendmsg+0x6e2/0x800 net/socket.c:2454
___sys_sendmsg+0xf3/0x170 net/socket.c:2508
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2537
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
-> #1 (&blkcg->lock){....}-{2:2}:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:354 [inline]
blkg_create+0x47b/0x1030 block/blk-cgroup.c:301
blkcg_init_queue+0xfe/0x810 block/blk-cgroup.c:1206
__alloc_disk_node+0x260/0x610 block/genhd.c:1381
__blk_alloc_disk+0x35/0x70 block/genhd.c:1421
brd_alloc.part.0+0x27f/0x7a0 drivers/block/brd.c:391
brd_alloc drivers/block/brd.c:374 [inline]
brd_init+0x1b8/0x24b drivers/block/brd.c:477
do_one_initcall+0x103/0x650 init/main.c:1301
do_initcall_level init/main.c:1376 [inline]
do_initcalls init/main.c:1392 [inline]
do_basic_setup init/main.c:1411 [inline]
kernel_init_freeable+0x6b1/0x73a init/main.c:1618
kernel_init+0x1a/0x1d0 init/main.c:1507
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
-> #0 (&q->queue_lock){..-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3095 [inline]
check_prevs_add kernel/locking/lockdep.c:3214 [inline]
validate_chain kernel/locking/lockdep.c:3829 [inline]
__lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053
lock_acquire kernel/locking/lockdep.c:5665 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:379 [inline]
throtl_pending_timer_fn+0xf7/0x1690 block/blk-throttle.c:1152
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1444
expire_timers kernel/time/timer.c:1489 [inline]
__run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1760
__run_timers kernel/time/timer.c:1738 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1773
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649
arch_local_irq_restore arch/x86/include/asm/irqflags.h:137 [inline]
lockdep_unregister_key+0x279/0x460 kernel/locking/lockdep.c:6355
wq_unregister_lockdep kernel/workqueue.c:3512 [inline]
pwq_unbound_release_workfn+0x254/0x340 kernel/workqueue.c:3750
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
other info that might help us debug this:
Chain exists of:
&q->queue_lock --> &blkcg->lock --> (&sq->pending_timer)
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock((&sq->pending_timer));
lock(&blkcg->lock);
lock((&sq->pending_timer));
lock(&q->queue_lock);
*** DEADLOCK ***
3 locks held by kworker/1:1/27:
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc90000a2fda8 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffffc900001f0d70 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline]
#2: ffffc900001f0d70 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1434
stack backtrace:
CPU: 1 PID: 27 Comm: kworker/1:1 Not tainted 5.18.0-rc4-next-20220429-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events pwq_unbound_release_workfn
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3095 [inline]
check_prevs_add kernel/locking/lockdep.c:3214 [inline]
validate_chain kernel/locking/lockdep.c:3829 [inline]
__lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053
lock_acquire kernel/locking/lockdep.c:5665 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:379 [inline]
throtl_pending_timer_fn+0xf7/0x1690 block/blk-throttle.c:1152
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1444
expire_timers kernel/time/timer.c:1489 [inline]
__run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1760
__run_timers kernel/time/timer.c:1738 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1773
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:lockdep_unregister_key+0x279/0x460 kernel/locking/lockdep.c:6358
Code: e8 ec ea ff ff 4c 89 e7 e8 e4 c6 ff ff e8 8f c7 ff ff 9c 58 f6 c4 02 0f 85 43 01 00 00 41 f7 c6 00 02 00 00 0f 85 ec 00 00 00 22 79 08 00 48 b8 00 00 00 00 00 fc ff df 49 c7 44 05 00 00 00
RSP: 0018:ffffc90000a2fc38 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffff88801b9ef928 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801b9ef928 R08: ffffffff8bd8f440 R09: ffffffff9086b293
R10: fffffbfff210d652 R11: 000000000000182b R12: ffffffff9006f838
R13: 1ffff92000145f88 R14: 0000000000000246 R15: ffffffff901ff078
wq_unregister_lockdep kernel/workqueue.c:3512 [inline]
pwq_unbound_release_workfn+0x254/0x340 kernel/workqueue.c:3750
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
----------------
Code disassembly (best guess):
0: e8 ec ea ff ff callq 0xffffeaf1
5: 4c 89 e7 mov %r12,%rdi
8: e8 e4 c6 ff ff callq 0xffffc6f1
d: e8 8f c7 ff ff callq 0xffffc7a1
12: 9c pushfq
13: 58 pop %rax
14: f6 c4 02 test $0x2,%ah
17: 0f 85 43 01 00 00 jne 0x160
1d: 41 f7 c6 00 02 00 00 test $0x200,%r14d
24: 0f 85 ec 00 00 00 jne 0x116
* 2a: e8 22 79 08 00 callq 0x87951 <-- trapping instruction
2f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
36: fc ff df
39: 49 rex.WB
3a: c7 .byte 0xc7
3b: 44 rex.R
3c: 05 .byte 0x5
3d: 00 00 add %al,(%rax)