======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.5.2222/13163 is trying to acquire lock:
ffff8880284ecc30 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
ffff8880284ecc30 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0x111/0x1dd0 block/blk-throttle.c:1209
but task is already holding lock:
ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xcf/0x670 kernel/time/timer.c:1698
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 ((&sq->pending_timer)){+.-.}-{0:0}:
__timer_delete_sync+0xe1/0x2e0 kernel/time/timer.c:1556
del_timer_sync include/linux/timer.h:200 [inline]
throtl_pd_free+0x15/0x30 block/blk-throttle.c:504
blkcg_deactivate_policy+0x35f/0x5d0 block/blk-cgroup.c:1542
blk_throtl_exit+0xa6/0x140 block/blk-throttle.c:2424
blkcg_init_disk+0x38d/0x400 block/blk-cgroup.c:1319
__alloc_disk_node+0x2b3/0x570 block/genhd.c:1432
__blk_alloc_disk+0x2c/0x80 block/genhd.c:1471
alloc_dev drivers/md/dm.c:2057 [inline]
dm_create+0x46b/0xf90 drivers/md/dm.c:2261
dev_create+0x12e/0x2c0 drivers/md/dm-ioctl.c:887
ctl_ioctl drivers/md/dm-ioctl.c:2070 [inline]
dm_ctl_ioctl+0xa9c/0xec0 drivers/md/dm-ioctl.c:2092
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #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:351 [inline]
blkg_create+0xbe9/0x1390 block/blk-cgroup.c:322
blkcg_init_disk+0x272/0x400 block/blk-cgroup.c:1293
__alloc_disk_node+0x2b3/0x570 block/genhd.c:1432
__blk_alloc_disk+0x2c/0x80 block/genhd.c:1471
brd_alloc+0x377/0x760 drivers/block/brd.c:424
brd_init+0x125/0x1a5 drivers/block/brd.c:529
do_one_initcall+0x257/0x800 init/main.c:1271
do_initcall_level+0x13d/0x1ed init/main.c:1344
do_initcalls+0x4b/0x8a init/main.c:1360
kernel_init_freeable+0x401/0x5ab init/main.c:1599
kernel_init+0x19/0x1b0 init/main.c:1487
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
-> #0 (&q->queue_lock){..-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3162 [inline]
check_prevs_add kernel/locking/lockdep.c:3281 [inline]
validate_chain kernel/locking/lockdep.c:3897 [inline]
__lock_acquire+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171
lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:376 [inline]
throtl_pending_timer_fn+0x111/0x1dd0 block/blk-throttle.c:1209
call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x56c/0x810 kernel/time/timer.c:2023
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x291/0x910 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5866
lock_is_held include/linux/lockdep.h:288 [inline]
__might_resched+0xea/0x5f0 kernel/sched/core.c:9982
zap_pmd_range mm/memory.c:1574 [inline]
zap_pud_range mm/memory.c:1601 [inline]
zap_p4d_range mm/memory.c:1622 [inline]
unmap_page_range+0x20d5/0x25b0 mm/memory.c:1643
unmap_vmas+0x260/0x390 mm/memory.c:1728
unmap_region+0x216/0x300 mm/mmap.c:2348
do_mas_align_munmap+0xcda/0x12d0 mm/mmap.c:2600
do_mas_munmap+0x240/0x2b0 mm/mmap.c:2658
__vm_munmap+0x1aa/0x2d0 mm/mmap.c:2944
__do_sys_munmap mm/mmap.c:2969 [inline]
__se_sys_munmap mm/mmap.c:2966 [inline]
__x64_sys_munmap+0x5c/0x70 mm/mmap.c:2966
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
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 ***
2 locks held by syz.5.2222/13163:
#0: ffff88807e72d3d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_downgrade include/linux/mmap_lock.h:111 [inline]
#0: ffff88807e72d3d8 (&mm->mmap_lock){++++}-{3:3}, at: do_mas_align_munmap+0xc9a/0x12d0 mm/mmap.c:2597
#1: ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xcf/0x670 kernel/time/timer.c:1698
stack backtrace:
CPU: 1 PID: 13163 Comm: syz.5.2222 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
check_noncircular+0x2f8/0x400 kernel/locking/lockdep.c:2215
check_prev_add kernel/locking/lockdep.c:3162 [inline]
check_prevs_add kernel/locking/lockdep.c:3281 [inline]
validate_chain kernel/locking/lockdep.c:3897 [inline]
__lock_acquire+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171
lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:376 [inline]
throtl_pending_timer_fn+0x111/0x1dd0 block/blk-throttle.c:1209
call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x56c/0x810 kernel/time/timer.c:2023
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x291/0x910 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5866
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90003bff578 EFLAGS: 00000206
RAX: 06834c18ead4fe00 RBX: ffff88802e0e1e00 RCX: 06834c18ead4fe00
RDX: 0000000000000000 RSI: ffffffff8aac2e40 RDI: ffffffff8afe72a0
RBP: 0000000000000000 R08: ffff8880283e0f63 R09: 1ffff1100507c1ec
R10: dffffc0000000000 R11: ffffed100507c1ed R12: 0000000000000001
R13: 0000000000000246 R14: ffffffff8db2db60 R15: ffff88802e0e2908
lock_is_held include/linux/lockdep.h:288 [inline]
__might_resched+0xea/0x5f0 kernel/sched/core.c:9982
zap_pmd_range mm/memory.c:1574 [inline]
zap_pud_range mm/memory.c:1601 [inline]
zap_p4d_range mm/memory.c:1622 [inline]
unmap_page_range+0x20d5/0x25b0 mm/memory.c:1643
unmap_vmas+0x260/0x390 mm/memory.c:1728
unmap_region+0x216/0x300 mm/mmap.c:2348
do_mas_align_munmap+0xcda/0x12d0 mm/mmap.c:2600
do_mas_munmap+0x240/0x2b0 mm/mmap.c:2658
__vm_munmap+0x1aa/0x2d0 mm/mmap.c:2944
__do_sys_munmap mm/mmap.c:2969 [inline]
__se_sys_munmap mm/mmap.c:2966 [inline]
__x64_sys_munmap+0x5c/0x70 mm/mmap.c:2966
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f466fd9f947
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 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:00007f4670d3be08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000200000 RCX: 00007f466fd9f947
RDX: 0000000000200000 RSI: 0000000008400000 RDI: 00007f4665bf7000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f4670d3bee0 R14: 00007f4670d3bea0 R15: 00007f4665bf7000
----------------
Code disassembly (best guess):
0: 75 40 jne 0x42
2: 48 c7 04 24 00 00 00 movq $0x0,(%rsp)
9: 00
a: 9c pushf
b: 8f 04 24 pop (%rsp)
e: f7 04 24 00 02 00 00 testl $0x200,(%rsp)
15: 75 46 jne 0x5d
17: 41 f7 c5 00 02 00 00 test $0x200,%r13d
1e: 74 01 je 0x21
20: fb sti
21: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax
28: 00 00
* 2a: 48 3b 44 24 08 cmp 0x8(%rsp),%rax <-- trapping instruction
2f: 75 3c jne 0x6d
31: 89 e8 mov %ebp,%eax
33: 48 83 c4 10 add $0x10,%rsp
37: 5b pop %rbx
38: 41 5c pop %r12
3a: 41 5d pop %r13
3c: 41 5e pop %r14
3e: 41 5f pop %r15