[syzbot] inconsistent lock state in sync_timeline_debug_remove

From: syzbot
Date: Mon Feb 14 2022 - 03:30:24 EST


Hello,

syzbot found the following issue on:

HEAD commit: f4bc5bbb5fef Merge tag 'nfsd-5.17-2' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10fc74c2700000
kernel config: https://syzkaller.appspot.com/x/.config?x=266de9da75c71a45
dashboard link: https://syzkaller.appspot.com/bug?extid=7dcd254b8987a29f6450
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10c73c74700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1440451c700000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10a40d84700000
final oops: https://syzkaller.appspot.com/x/report.txt?x=12a40d84700000
console output: https://syzkaller.appspot.com/x/log.txt?x=14a40d84700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7dcd254b8987a29f6450@xxxxxxxxxxxxxxxxxxxxxxxxx

================================
WARNING: inconsistent lock state
5.17.0-rc3-syzkaller-00043-gf4bc5bbb5fef #0 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
syz-executor198/3596 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffffffff8c7096d8 (sync_timeline_list_lock){?.+.}-{2:2}, at: sync_timeline_debug_remove+0x25/0x190 drivers/dma-buf/sync_debug.c:31
{HARDIRQ-ON-W} state was registered at:
__trace_hardirqs_on_caller kernel/locking/lockdep.c:4224 [inline]
lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4292 [inline]
lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4244
trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline]
_raw_spin_unlock_irq+0x1f/0x40 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:399 [inline]
sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline]
sync_info_debugfs_show+0xeb/0x200 drivers/dma-buf/sync_debug.c:153
seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230
seq_read+0x3e8/0x5c0 fs/seq_file.c:162
vfs_read+0x1b5/0x600 fs/read_write.c:479
ksys_read+0x12d/0x250 fs/read_write.c:619
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
irq event stamp: 5708
hardirqs last enabled at (5707): [<ffffffff894db1ef>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline]
hardirqs last enabled at (5707): [<ffffffff894db1ef>] _raw_spin_unlock_irq+0x1f/0x40 kernel/locking/spinlock.c:202
hardirqs last disabled at (5708): [<ffffffff894a992b>] sysvec_irq_work+0xb/0xc0 arch/x86/kernel/irq_work.c:17
softirqs last enabled at (5570): [<ffffffff84da6fd6>] spin_unlock_bh include/linux/spinlock.h:394 [inline]
softirqs last enabled at (5570): [<ffffffff84da6fd6>] __tun_set_ebpf+0xf6/0x1c0 drivers/net/tun.c:2245
softirqs last disabled at (5568): [<ffffffff84da6f83>] spin_lock_bh include/linux/spinlock.h:354 [inline]
softirqs last disabled at (5568): [<ffffffff84da6f83>] __tun_set_ebpf+0xa3/0x1c0 drivers/net/tun.c:2241

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(sync_timeline_list_lock);
<Interrupt>
lock(sync_timeline_list_lock);

*** DEADLOCK ***

no locks held by syz-executor198/3596.

stack backtrace:
CPU: 0 PID: 3596 Comm: syz-executor198 Not tainted 5.17.0-rc3-syzkaller-00043-gf4bc5bbb5fef #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_usage_bug kernel/locking/lockdep.c:203 [inline]
valid_state kernel/locking/lockdep.c:3945 [inline]
mark_lock_irq kernel/locking/lockdep.c:4148 [inline]
mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4605
mark_usage kernel/locking/lockdep.c:4497 [inline]
__lock_acquire+0x1499/0x5470 kernel/locking/lockdep.c:4981
lock_acquire kernel/locking/lockdep.c:5639 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
sync_timeline_debug_remove+0x25/0x190 drivers/dma-buf/sync_debug.c:31
sync_timeline_free drivers/dma-buf/sw_sync.c:104 [inline]
kref_put include/linux/kref.h:65 [inline]
sync_timeline_put drivers/dma-buf/sw_sync.c:116 [inline]
timeline_fence_release+0x263/0x340 drivers/dma-buf/sw_sync.c:144
dma_fence_release+0x2ee/0x590 drivers/dma-buf/dma-fence.c:549
kref_put include/linux/kref.h:65 [inline]
dma_fence_put include/linux/dma-fence.h:276 [inline]
dma_fence_array_release+0x1e4/0x2b0 drivers/dma-buf/dma-fence-array.c:120
dma_fence_release+0x2ee/0x590 drivers/dma-buf/dma-fence.c:549
kref_put include/linux/kref.h:65 [inline]
dma_fence_put include/linux/dma-fence.h:276 [inline]
irq_dma_fence_array_work+0xa5/0xd0 drivers/dma-buf/dma-fence-array.c:52
irq_work_single+0x120/0x270 kernel/irq_work.c:211
irq_work_run_list+0x91/0xc0 kernel/irq_work.c:242
irq_work_run+0x54/0xd0 kernel/irq_work.c:251
__sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22
sysvec_irq_work+0x8e/0xc0 arch/x86/kernel/irq_work.c:17
</IRQ>
<TASK>
asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:664
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 4e a1 0f f8 48 89 ef e8 06 17 10 f8 e8 b1 0b 31 f8 fb bf 01 00 00 00 <e8> 46 ca 02 f8 65 8b 05 bf bd b4 76 85 c0 74 02 5d c3 e8 2b 93 b2
RSP: 0018:ffffc90001f5fe18 EFLAGS: 00000206
RAX: 000000000000164b RBX: 00000000ffffffff RCX: 1ffffffff1b27381
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff8880153ff050 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817ebdd8 R11: 0000000000000000 R12: ffff8880153ff000
R13: dffffc0000000000 R14: ffff8880153ff000 R15: ffff8880153ff050
spin_unlock_irq include/linux/spinlock.h:399 [inline]
sw_sync_debugfs_release+0x160/0x240 drivers/dma-buf/sw_sync.c:321
__fput+0x286/0x9f0 fs/file_table.c:313
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbe1817b7e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fbe17901208 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fbe181fd4f8 RCX: 00007fbe1817b7e9
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000003
RBP: 00007fbe181fd4f0 R08: 00007fbe17901700 R09: 0000000000000000
R10: 00007fbe17901700 R11: 0000000000000246 R12: 00007fbe181fd4fc
R1
----------------
Code disassembly (best guess):
0: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
5: 55 push %rbp
6: 48 8b 74 24 08 mov 0x8(%rsp),%rsi
b: 48 89 fd mov %rdi,%rbp
e: 48 83 c7 18 add $0x18,%rdi
12: e8 4e a1 0f f8 callq 0xf80fa165
17: 48 89 ef mov %rbp,%rdi
1a: e8 06 17 10 f8 callq 0xf8101725
1f: e8 b1 0b 31 f8 callq 0xf8310bd5
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 46 ca 02 f8 callq 0xf802ca75 <-- trapping instruction
2f: 65 8b 05 bf bd b4 76 mov %gs:0x76b4bdbf(%rip),%eax # 0x76b4bdf5
36: 85 c0 test %eax,%eax
38: 74 02 je 0x3c
3a: 5d pop %rbp
3b: c3 retq
3c: e8 .byte 0xe8
3d: 2b .byte 0x2b
3e: 93 xchg %eax,%ebx
3f: b2 .byte 0xb2


---
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