======================================================
WARNING: possible circular locking dependency detected
6.1.16-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/3665 is trying to acquire lock:
ffff88801ec3ece0 (&q->queue_lock){..-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline]
ffff88801ec3ece0 (&q->queue_lock){..-.}-{2:2}, at: throtl_pending_timer_fn+0x10d/0x1be0 block/blk-throttle.c:1193
but task is already holding lock:
ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
ffffc900001e0bc0 ((&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
__kernel_text_address+0x30/0x40 kernel/extable.c:92
unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1724 [inline]
slab_free_freelist_hook mm/slub.c:1750 [inline]
slab_free mm/slub.c:3661 [inline]
kmem_cache_free+0x2b6/0x580 mm/slub.c:3683
free_buffer_head+0x45/0xb0 fs/buffer.c:2915
try_to_free_buffers+0x302/0x600 fs/buffer.c:2856
block_invalidate_folio+0x67d/0xa00 fs/buffer.c:1526
folio_invalidate mm/truncate.c:159 [inline]
truncate_cleanup_folio+0x1e3/0x5e0 mm/truncate.c:179
truncate_inode_pages_range+0x2e6/0x1340 mm/truncate.c:369
ext4_evict_inode+0x450/0x1230 fs/ext4/inode.c:221
evict+0x2a4/0x620 fs/inode.c:664
do_unlinkat+0x502/0x940 fs/namei.c:4327
__do_sys_unlink fs/namei.c:4368 [inline]
__se_sys_unlink fs/namei.c:4366 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4366
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
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.4/3665:
#0: ffff888018fa6460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
#1: ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#1: ffffc900001e0bc0 ((&sq->pending_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x840 kernel/time/timer.c:1464
stack backtrace:
CPU: 1 PID: 3665 Comm: syz-executor.4 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:__kernel_text_address+0x30/0x40 kernel/extable.c:92
Code: 00 00 00 85 c0 0f 95 c0 48 c7 c1 00 80 8e 8f 48 39 cb 0f 93 c1 48 c7 c2 20 d7 a3 8f 48 39 d3 0f 92 c2 20 ca 08 c2 0f b6 c2 5b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 41 56 53 48 89
RSP: 0018:ffffc9000414f318 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc9000414f388 RCX: ffffffff8f8e8000
RDX: ffffffff8fa3d701 RSI: ffffc90004148000 RDI: ffffffff81bcf996
RBP: ffffc9000414f3d0 R08: ffffc9000414f9d0 R09: ffffc9000414f390
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801e233a80
R13: ffffffff81785090 R14: dffffc0000000000 R15: 1ffff92000829e71
unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1724 [inline]
slab_free_freelist_hook mm/slub.c:1750 [inline]
slab_free mm/slub.c:3661 [inline]
kmem_cache_free+0x2b6/0x580 mm/slub.c:3683
free_buffer_head+0x45/0xb0 fs/buffer.c:2915
try_to_free_buffers+0x302/0x600 fs/buffer.c:2856
block_invalidate_folio+0x67d/0xa00 fs/buffer.c:1526
folio_invalidate mm/truncate.c:159 [inline]
truncate_cleanup_folio+0x1e3/0x5e0 mm/truncate.c:179
truncate_inode_pages_range+0x2e6/0x1340 mm/truncate.c:369
ext4_evict_inode+0x450/0x1230 fs/ext4/inode.c:221
evict+0x2a4/0x620 fs/inode.c:664
do_unlinkat+0x502/0x940 fs/namei.c:4327
__do_sys_unlink fs/namei.c:4368 [inline]
__se_sys_unlink fs/namei.c:4366 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4366
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
RIP: 0033:0x7fe02248ba67
Code: 73 01 c3 48 c7 c1 b8 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 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe0ce5f5e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe02248ba67
RDX: 00007ffe0ce5f620 RSI: 00007ffe0ce5f620 RDI: 00007ffe0ce5f6b0
RBP: 00007ffe0ce5f6b0 R08: 0000000000000001 R09: 00007ffe0ce5f480
R10: 00005555564e98e3 R11: 0000000000000206 R12: 00007fe0224e6b24
R13: 00007ffe0ce60770 R14: 00005555564e9810 R15: 00007ffe0ce607b0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 85 c0 0f 95 c0 add %al,-0x3f6af040(%rbp)
8: 48 c7 c1 00 80 8e 8f mov $0xffffffff8f8e8000,%rcx
f: 48 39 cb cmp %rcx,%rbx
12: 0f 93 c1 setae %cl
15: 48 c7 c2 20 d7 a3 8f mov $0xffffffff8fa3d720,%rdx
1c: 48 39 d3 cmp %rdx,%rbx
1f: 0f 92 c2 setb %dl
22: 20 ca and %cl,%dl
24: 08 c2 or %al,%dl
26: 0f b6 c2 movzbl %dl,%eax
29: 5b pop %rbx
* 2a: c3 retq <-- trapping instruction
2b: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1)
32: 00 00 00
35: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
3a: 55 push %rbp
3b: 41 56 push %r14
3d: 53 push %rbx
3e: 48 rex.W
3f: 89 .byte 0x89