======================================================
WARNING: possible circular locking dependency detected
6.0.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/8326 is trying to acquire lock:
ffff888146f800d0 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline]
ffff888146f800d0 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0xe9/0xfb0 block/blk-throttle.c:1152
but task is already holding lock:
ffffc900001e0be0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
ffffc900001e0be0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbb/0x210 kernel/time/timer.c:1464
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 ((&sq->pending_timer)){+.-.}-{0:0}:
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
del_timer_sync+0xec/0x2a0 kernel/time/timer.c:1417
throtl_pd_free+0x15/0x40 block/blk-throttle.c:500
blkcg_deactivate_policy+0x328/0x540 block/blk-cgroup.c:1523
blk_throtl_exit+0x86/0x120 block/blk-throttle.c:2337
blkcg_init_queue+0x281/0x300 block/blk-cgroup.c:1304
__alloc_disk_node+0x2ce/0x590 block/genhd.c:1366
__blk_mq_alloc_disk+0x11b/0x1e0 block/blk-mq.c:3942
loop_add+0x325/0x9b0 drivers/block/loop.c:1983
loop_control_ioctl+0x108/0x770 drivers/block/loop.c:2155
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #1 (&blkcg->lock){....}-{2:2}:
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
__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:349 [inline]
blkg_create+0x949/0x10a0 block/blk-cgroup.c:344
blkcg_init_queue+0xb9/0x300 block/blk-cgroup.c:1285
__alloc_disk_node+0x2ce/0x590 block/genhd.c:1366
__blk_alloc_disk+0x2c/0x80 block/genhd.c:1405
brd_alloc+0x315/0x720 drivers/block/brd.c:391
brd_init+0x102/0x1c6 drivers/block/brd.c:477
do_one_initcall+0x1b9/0x3e0 init/main.c:1296
do_initcall_level+0x168/0x218 init/main.c:1369
do_initcalls+0x4b/0x8c init/main.c:1385
kernel_init_freeable+0x3f1/0x57b init/main.c:1623
kernel_init+0x19/0x2b0 init/main.c:1512
ret_from_fork+0x1f/0x30
-> #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+0x1873/0x6c00 kernel/locking/lockdep.c:3829
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:374 [inline]
throtl_pending_timer_fn+0xe9/0xfb0 block/blk-throttle.c:1152
call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x772/0x980 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x362/0x773 kernel/softirq.c:571
__irq_exit_rcu+0xcf/0x150 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x16/0x20
native_save_fl arch/x86/include/asm/irqflags.h:35 [inline]
arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
lock_is_held_type+0x62/0x180 kernel/locking/lockdep.c:5705
lock_is_held include/linux/lockdep.h:283 [inline]
rcu_read_lock_sched_held+0x87/0x110 kernel/rcu/update.c:125
trace_lock_acquire+0x7f/0x1d0 include/trace/events/lock.h:24
lock_acquire+0xa4/0x3c0 kernel/locking/lockdep.c:5637
rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:280
rcu_read_lock include/linux/rcupdate.h:706 [inline]
folio_memcg_lock+0x8c/0x5b0 mm/memcontrol.c:2044
page_remove_rmap+0x2d/0x460 mm/rmap.c:1432
zap_pte_range+0x9c4/0x19b0 mm/memory.c:1454
zap_pmd_range+0x587/0x690 mm/memory.c:1575
zap_pud_range mm/memory.c:1604 [inline]
zap_p4d_range mm/memory.c:1625 [inline]
unmap_page_range+0x466/0x7a0 mm/memory.c:1646
unmap_vmas+0x1f7/0x380 mm/memory.c:1731
exit_mmap+0x1b4/0x520 mm/mmap.c:3116
__mmput+0x111/0x3a0 kernel/fork.c:1187
exit_mm+0x1ef/0x2c0 kernel/exit.c:510
do_exit+0x4e1/0x20a0 kernel/exit.c:782
do_group_exit+0x23b/0x2f0 kernel/exit.c:925
get_signal+0x172f/0x1780 kernel/signal.c:2857
arch_do_signal_or_restart+0x7b/0x730 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop+0x74/0x150 kernel/entry/common.c:166
exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:294
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
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 syz-executor.4/8326:
#0: ffff8880779c7128 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880779c7128 (&mm->mmap_lock#2){++++}-{3:3}, at: exit_mmap+0x114/0x520 mm/mmap.c:3101
#1: ffff8880180c1a38 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#1: ffff8880180c1a38 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: zap_pte_range+0x233/0x19b0 mm/memory.c:1418
#2: ffffc900001e0be0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#2: ffffc900001e0be0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbb/0x210 kernel/time/timer.c:1464
stack backtrace:
CPU: 1 PID: 8326 Comm: syz-executor.4 Not tainted 6.0.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
check_noncircular+0x2cc/0x390 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+0x1873/0x6c00 kernel/locking/lockdep.c:3829
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:374 [inline]
throtl_pending_timer_fn+0xe9/0xfb0 block/blk-throttle.c:1152
call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x772/0x980 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x362/0x773 kernel/softirq.c:571
__irq_exit_rcu+0xcf/0x150 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x16/0x20
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:40 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:75 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:107 [inline]
RIP: 0010:lock_is_held_type+0x62/0x180 kernel/locking/lockdep.c:5705
Code: 85 e6 00 00 00 65 4c 8b 2c 25 00 6f 02 00 41 83 bd 74 0a 00 00 00 0f 85 cf 00 00 00 41 89 f6 49 89 ff 9c 8f 04 24 4c 8b 24 24 48 c7 c7 60 9c 8d 8a e8 a1 14 00 00 65 ff 05 0a f3 df 75 41 83
RSP: 0018:ffffc9000b747098 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff920016e8e1c RCX: 0000000080000002
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8cb231a0
RBP: 00000000ffffffff R08: dffffc0000000000 R09: fffffbfff1c1648e
R10: fffffbfff1c1648e R11: 1ffffffff1c1648d R12: 0000000000000246
R13: ffff8880482a1d80 R14: 00000000ffffffff R15: ffffffff8cb231a0
lock_is_held include/linux/lockdep.h:283 [inline]
rcu_read_lock_sched_held+0x87/0x110 kernel/rcu/update.c:125
trace_lock_acquire+0x7f/0x1d0 include/trace/events/lock.h:24
lock_acquire+0xa4/0x3c0 kernel/locking/lockdep.c:5637
rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:280
rcu_read_lock include/linux/rcupdate.h:706 [inline]
folio_memcg_lock+0x8c/0x5b0 mm/memcontrol.c:2044
page_remove_rmap+0x2d/0x460 mm/rmap.c:1432
zap_pte_range+0x9c4/0x19b0 mm/memory.c:1454
zap_pmd_range+0x587/0x690 mm/memory.c:1575
zap_pud_range mm/memory.c:1604 [inline]
zap_p4d_range mm/memory.c:1625 [inline]
unmap_page_range+0x466/0x7a0 mm/memory.c:1646
unmap_vmas+0x1f7/0x380 mm/memory.c:1731
exit_mmap+0x1b4/0x520 mm/mmap.c:3116
__mmput+0x111/0x3a0 kernel/fork.c:1187
exit_mm+0x1ef/0x2c0 kernel/exit.c:510
do_exit+0x4e1/0x20a0 kernel/exit.c:782
do_group_exit+0x23b/0x2f0 kernel/exit.c:925
get_signal+0x172f/0x1780 kernel/signal.c:2857
arch_do_signal_or_restart+0x7b/0x730 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop+0x74/0x150 kernel/entry/common.c:166
exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:294
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f3ca8a89409
Code: Unable to access opcode bytes at RIP 0x7f3ca8a893df.
RSP: 002b:00007f3ca9c93218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f3ca8b9bf88 RCX: 00007f3ca8a89409
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3ca8b9bf88
RBP: 00007f3ca8b9bf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3ca8b9bf8c
R13: 00007ffed5fc06bf R14: 00007f3ca9c93300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: 85 e6 test %esp,%esi
2: 00 00 add %al,(%rax)
4: 00 65 4c add %ah,0x4c(%rbp)
7: 8b 2c 25 00 6f 02 00 mov 0x26f00,%ebp
e: 41 83 bd 74 0a 00 00 cmpl $0x0,0xa74(%r13)
15: 00
16: 0f 85 cf 00 00 00 jne 0xeb
1c: 41 89 f6 mov %esi,%r14d
1f: 49 89 ff mov %rdi,%r15
22: 9c pushfq
23: 8f 04 24 popq (%rsp)
26: 4c 8b 24 24 mov (%rsp),%r12
* 2a: fa cli <-- trapping instruction
2b: 48 c7 c7 60 9c 8d 8a mov $0xffffffff8a8d9c60,%rdi
32: e8 a1 14 00 00 callq 0x14d8
37: 65 ff 05 0a f3 df 75 incl %gs:0x75dff30a(%rip) # 0x75dff348
3e: 41 rex.B
3f: 83 .byte 0x83