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From:   Hao Sun <sunhao.th@gmail.com>
Date:   Thu, 14 Oct 2021 10:45:24 +0800
Message-ID: <CACkBjsa74dyF4TiwxH1yKuyaGcPQSEP9mvPedBCaskGU7g5vdw@mail.gmail.com>
Subject: possible deadlock in io_poll_double_wake
To:     Pavel Begunkov <asml.silence@gmail.com>,
        Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Precedence: bulk

Hello,

When using Healer to fuzz the latest Linux kernel, the following crash
was triggered.

HEAD commit: 64570fbc14f8 Linux 5.15-rc5
git tree: upstream
console output:
https://drive.google.com/file/d/1vA465O1bvHG4dfD07CNI-lcjbFYaD-nK/view?usp=sharing
kernel config: https://drive.google.com/file/d/1em3xgUIMNN_-LUUdySzwN-UDPc3qiiKD/view?usp=sharing
C reproducer: https://drive.google.com/file/d/13EMtDAujxvvBRb3m1gV1zXsp4gkRFJSS/view?usp=sharing
Syzlang reproducer:
https://drive.google.com/file/d/1dFk5ujvk-lnr_KzNGboFm9fvwYdETowv/view?usp=sharing

If you fix this issue, please add the following tag to the commit:
Reported-by: Hao Sun <sunhao.th@gmail.com>

============================================
WARNING: possible recursive locking detected
5.15.0-rc5 #3 Not tainted
--------------------------------------------
swapper/0/0 is trying to acquire lock:
ffff88810f5cd130 (&runtime->sleep){..-.}-{2:2}, at:
io_poll_double_wake+0x2be/0x800 fs/io_uring.c:5418

but task is already holding lock:
ffff88810f5cf130 (&runtime->sleep){..-.}-{2:2}, at:
__wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137

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

       CPU0
       ----
  lock(&runtime->sleep);
  lock(&runtime->sleep);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by swapper/0/0:
 #0: ffffc90000007d68 ((&dpcm->timer)){+.-.}-{0:0}, at:
lockdep_copy_map include/linux/lockdep.h:35 [inline]
 #0: ffffc90000007d68 ((&dpcm->timer)){+.-.}-{0:0}, at:
call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1411
 #1: ffff888100fc6108 (&group->lock){..-.}-{2:2}, at:
_snd_pcm_stream_lock_irqsave+0x9f/0xd0 sound/core/pcm_native.c:170
 #2: ffff88810f5cf130 (&runtime->sleep){..-.}-{2:2}, at:
__wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.0-rc5 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline]
 check_deadlock kernel/locking/lockdep.c:2987 [inline]
 validate_chain kernel/locking/lockdep.c:3776 [inline]
 __lock_acquire.cold+0x168/0x3c3 kernel/locking/lockdep.c:5015
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5590
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
 io_poll_double_wake+0x2be/0x800 fs/io_uring.c:5418
 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108
 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138
 snd_pcm_update_state+0x3d4/0x540 sound/core/pcm_lib.c:203
 snd_pcm_update_hw_ptr0+0xe79/0x2090 sound/core/pcm_lib.c:464
 snd_pcm_period_elapsed_under_stream_lock+0x15a/0x230 sound/core/pcm_lib.c:1816
 snd_pcm_period_elapsed+0x28/0x50 sound/core/pcm_lib.c:1848
 loopback_jiffies_timer_function+0x1eb/0x270 sound/drivers/aloop.c:668
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x6b0/0xa90 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb6/0x1d0 kernel/time/timer.c:1747
 __do_softirq+0x1d7/0x93b kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu kernel/softirq.c:636 [inline]
 irq_exit_rcu+0xf2/0x130 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:717
Code: 1b 51 88 f8 e9 6f fe ff ff e8 11 51 88 f8 e9 3d fe ff ff e8 17
31 fd ff cc cc cc cc cc cc cc eb 07 0f 00 2d 47 99 50 00 fb f4 <c3> 0f
1f 40 00 41 54 be 08 00 00 00 53 65 48 8b 1c 25 40 f0 01 00
RSP: 0018:ffffffff8b607e28 EFLAGS: 00000206
RAX: 00000000001543c3 RBX: 0000000000000000 RCX: ffffffff8932d572
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100c7c6542
R10: ffff888063e32a0b R11: ffffed100c7c6541 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8d6d8590 R15: 0000000000000000
 default_idle_call+0xc4/0x420 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x3f9/0x570 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_kernel+0x47a/0x49b init/main.c:1141
 secondary_startup_64_no_verify+0xb0/0xbb
----------------
Code disassembly (best guess):
   0: 1b 51 88              sbb    -0x78(%rcx),%edx
   3: f8                    clc
   4: e9 6f fe ff ff        jmpq   0xfffffe78
   9: e8 11 51 88 f8        callq  0xf888511f
   e: e9 3d fe ff ff        jmpq   0xfffffe50
  13: e8 17 31 fd ff        callq  0xfffd312f
  18: cc                    int3
  19: cc                    int3
  1a: cc                    int3
  1b: cc                    int3
  1c: cc                    int3
  1d: cc                    int3
  1e: cc                    int3
  1f: eb 07                jmp    0x28
  21: 0f 00 2d 47 99 50 00 verw   0x509947(%rip)        # 0x50996f
  28: fb                    sti
  29: f4                    hlt
* 2a: c3                    retq <-- trapping instruction
  2b: 0f 1f 40 00          nopl   0x0(%rax)
  2f: 41 54                push   %r12
  31: be 08 00 00 00        mov    $0x8,%esi
  36: 53                    push   %rbx
  37: 65 48 8b 1c 25 40 f0 mov    %gs:0x1f040,%rbx
  3e: 01 00