======================================================
WARNING: possible circular locking dependency detected
6.1.16-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/21084 is trying to acquire lock:
ffff888147248920 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline]
ffff888147248920 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193
but task is already holding lock:
ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 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+0x23a/0x630 kernel/locking/lockdep.c:5669
del_timer_sync+0x111/0x2e0 kernel/time/timer.c:1417
throtl_pd_free+0x15/0x40 block/blk-throttle.c:493
blkcg_deactivate_policy+0x32d/0x550 block/blk-cgroup.c:1499
blk_throtl_exit+0xa6/0x140 block/blk-throttle.c:2406
disk_release+0x1dd/0x380 block/genhd.c:1171
device_release+0x91/0x1c0
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x224/0x460 lib/kobject.c:729
do_floppy_init+0x373/0xc59 drivers/block/floppy.c:4758
async_run_entry_fn+0xa2/0x410 kernel/async.c:127
process_one_work+0x909/0x1380 kernel/workqueue.c:2289
worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436
kthread+0x268/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
-> #1 (&blkcg->lock){....}-{2:2}:
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__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:350 [inline]
blkg_create+0xa94/0x1280 block/blk-cgroup.c:336
blkcg_init_disk+0xee/0x350 block/blk-cgroup.c:1260
__alloc_disk_node+0x2ce/0x590 block/genhd.c:1385
__blk_alloc_disk+0x2c/0x80 block/genhd.c:1424
brd_alloc+0x2f9/0x6a0 drivers/block/brd.c:397
brd_init+0x100/0x1c2 drivers/block/brd.c:484
do_one_initcall+0x2d6/0xa80 init/main.c:1303
do_initcall_level+0x157/0x207 init/main.c:1376
do_initcalls+0x49/0x86 init/main.c:1392
kernel_init_freeable+0x473/0x61f init/main.c:1631
kernel_init+0x19/0x290 init/main.c:1519
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
-> #0 (&q->queue_lock){..-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:375 [inline]
throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193
call_timer_fn+0x200/0x840 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x30d/0xb1b kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x155/0x240 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:1107
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
put_page_testzero include/linux/mm.h:763 [inline]
folio_put_testzero include/linux/mm.h:769 [inline]
release_pages+0x33b/0x2b40 mm/swap.c:1013
tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261
zap_pte_range mm/memory.c:1515 [inline]
zap_pmd_range mm/memory.c:1564 [inline]
zap_pud_range mm/memory.c:1593 [inline]
zap_p4d_range mm/memory.c:1614 [inline]
unmap_page_range+0x2112/0x26e0 mm/memory.c:1635
unmap_vmas+0x3c4/0x560 mm/memory.c:1720
exit_mmap+0x24d/0x970 mm/mmap.c:3089
__mmput+0x115/0x3c0 kernel/fork.c:1188
exit_mm+0x226/0x300 kernel/exit.c:563
do_exit+0x67e/0x2300 kernel/exit.c:856
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
get_signal+0x16f7/0x17d0 kernel/signal.c:2858
arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x60/0x2d0 kernel/entry/common.c:296
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 ***
2 locks held by syz-executor.0/21084:
#0: ffff888022f01f58 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline]
#0: ffff888022f01f58 (&mm->mmap_lock#2){++++}-{3:3}, at: exit_mmap+0x1c0/0x970 mm/mmap.c:3074
#1: ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#1: ffffc90000007bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 kernel/time/timer.c:1464
stack backtrace:
CPU: 0 PID: 21084 Comm: syz-executor.0 Not tainted 6.1.16-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x23a/0x630 kernel/locking/lockdep.c:5669
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:375 [inline]
throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193
call_timer_fn+0x200/0x840 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x30d/0xb1b kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x155/0x240 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:1107
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:put_page_testzero include/linux/mm.h:763 [inline]
RIP: 0010:folio_put_testzero include/linux/mm.h:769 [inline]
RIP: 0010:release_pages+0x33b/0x2b40 mm/swap.c:1013
Code: eb 6a 24 00 4c 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 ab 12 00 00 41 8b 1f 31 ff 89 de e8 bc 08 ce ff 85 db 4c 8b 64 24 10 <0f> 84 40 25 00 00 4c 89 ff be 04 00 00 00 e8 c2 6a 24 00 31 db f0
RSP: 0018:ffffc9000c02f160 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000004 RCX: ffffffff81bc5ba5
RDX: ffff88807db21d40 RSI: 0000000000000004 RDI: 0000000000000000
RBP: ffffc9000c02f2e0 R08: ffffffff81bc5bc4 R09: fffff940003b69ff
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000159
R13: 0000000000000000 R14: ffffea0001db4fc0 R15: ffffea0001db4ff4
tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261
zap_pte_range mm/memory.c:1515 [inline]
zap_pmd_range mm/memory.c:1564 [inline]
zap_pud_range mm/memory.c:1593 [inline]
zap_p4d_range mm/memory.c:1614 [inline]
unmap_page_range+0x2112/0x26e0 mm/memory.c:1635
unmap_vmas+0x3c4/0x560 mm/memory.c:1720
exit_mmap+0x24d/0x970 mm/mmap.c:3089
__mmput+0x115/0x3c0 kernel/fork.c:1188
exit_mm+0x226/0x300 kernel/exit.c:563
do_exit+0x67e/0x2300 kernel/exit.c:856
do_group_exit+0x202/0x2b0 kernel/exit.c:1019
get_signal+0x16f7/0x17d0 kernel/signal.c:2858
arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:869
exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x60/0x2d0 kernel/entry/common.c:296
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f218428c0f9
Code: Unable to access opcode bytes at 0x7f218428c0cf.
RSP: 002b:00007f2184f45218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f21843abf88 RCX: 00007f218428c0f9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f21843abf88
RBP: 00007f21843abf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f21843abf8c
R13: 00007ffe980af41f R14: 00007f2184f45300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: eb 6a jmp 0x6c
2: 24 00 and $0x0,%al
4: 4c 89 f8 mov %r15,%rax
7: 48 c1 e8 03 shr $0x3,%rax
b: 0f b6 04 18 movzbl (%rax,%rbx,1),%eax
f: 84 c0 test %al,%al
11: 0f 85 ab 12 00 00 jne 0x12c2
17: 41 8b 1f mov (%r15),%ebx
1a: 31 ff xor %edi,%edi
1c: 89 de mov %ebx,%esi
1e: e8 bc 08 ce ff callq 0xffce08df
23: 85 db test %ebx,%ebx
25: 4c 8b 64 24 10 mov 0x10(%rsp),%r12
* 2a: 0f 84 40 25 00 00 je 0x2570 <-- trapping instruction
30: 4c 89 ff mov %r15,%rdi
33: be 04 00 00 00 mov $0x4,%esi
38: e8 c2 6a 24 00 callq 0x246aff
3d: 31 db xor %ebx,%ebx
3f: f0 lock