syzbot


possible deadlock in snd_timer_interrupt

Status: fixed on 2021/11/10 00:50
Reported-by: syzbot+17c16b868e6af41acdd4@syzkaller.appspotmail.com
Fix commit: f671a691e299 fcntl: fix potential deadlocks for &fown_struct.lock
First crash: 557d, last: 453d

Cause bisection: introduced by (bisect log) :
commit e918188611f073063415f40fae568fa4d86d9044
Author: Boqun Feng <boqun.feng@gmail.com>
Date: Fri Aug 7 07:42:20 2020 +0000

  locking: More accurate annotations for read_lock()

Crash: possible deadlock in snd_timer_interrupt (log)
Repro: C syz .config
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in snd_timer_interrupt (2) C error 29 173d 434d 23/24 upstream: reported C repro on 2021/11/21 18:39

Sample crash report:
========================================================
WARNING: possible irq lock inversion dependency detected
5.14.0-syzkaller #0 Not tainted
--------------------------------------------------------
syz-executor264/11611 just changed the state of lock:
ffff8880273b5948 (&timer->lock){..-.}-{2:2}, at: snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857
but this lock took another, SOFTIRQ-READ-unsafe lock in the past:
 (&new->fa_lock){.+.+}-{2:2}


and interrupts could create inverse lock ordering between them.


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

       CPU0                    CPU1
       ----                    ----
  lock(&new->fa_lock);
                               local_irq_disable();
                               lock(&timer->lock);
                               lock(&new->fa_lock);
  <Interrupt>
    lock(&timer->lock);

 *** DEADLOCK ***

2 locks held by syz-executor264/11611:
 #0: ffff888012bf0f28 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff888012bf0f28 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x285/0x11c0 arch/x86/mm/fault.c:1331
 #1: ffffc90000007d70 ((&priv->tlist)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline]
 #1: ffffc90000007d70 ((&priv->tlist)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1411

the shortest dependencies between 2nd lock and 1st lock:
 -> (&new->fa_lock){.+.+}-{2:2} {
    HARDIRQ-ON-R at:
                      lock_acquire kernel/locking/lockdep.c:5625 [inline]
                      lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
                      __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                      _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
                      kill_fasync_rcu fs/fcntl.c:1012 [inline]
                      kill_fasync fs/fcntl.c:1033 [inline]
                      kill_fasync+0x132/0x460 fs/fcntl.c:1026
                      fsnotify_add_event+0x3ba/0x500 fs/notify/notification.c:128
                      inotify_handle_inode_event+0x31b/0x5c0 fs/notify/inotify/inotify_fsnotify.c:119
                      fsnotify_handle_inode_event.isra.0+0x1b8/0x270 fs/notify/fsnotify.c:263
                      fsnotify_handle_event fs/notify/fsnotify.c:310 [inline]
                      send_to_group fs/notify/fsnotify.c:364 [inline]
                      fsnotify+0xc27/0x1050 fs/notify/fsnotify.c:541
                      fsnotify_parent include/linux/fsnotify.h:71 [inline]
                      fsnotify_file include/linux/fsnotify.h:90 [inline]
                      fsnotify_open include/linux/fsnotify.h:268 [inline]
                      do_sys_openat2+0x3a3/0x420 fs/open.c:1209
                      do_sys_open fs/open.c:1220 [inline]
                      __do_sys_open fs/open.c:1228 [inline]
                      __se_sys_open fs/open.c:1224 [inline]
                      __x64_sys_open+0x119/0x1c0 fs/open.c:1224
                      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
    SOFTIRQ-ON-R at:
                      lock_acquire kernel/locking/lockdep.c:5625 [inline]
                      lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
                      __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                      _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
                      kill_fasync_rcu fs/fcntl.c:1012 [inline]
                      kill_fasync fs/fcntl.c:1033 [inline]
                      kill_fasync+0x132/0x460 fs/fcntl.c:1026
                      fsnotify_add_event+0x3ba/0x500 fs/notify/notification.c:128
                      inotify_handle_inode_event+0x31b/0x5c0 fs/notify/inotify/inotify_fsnotify.c:119
                      fsnotify_handle_inode_event.isra.0+0x1b8/0x270 fs/notify/fsnotify.c:263
                      fsnotify_handle_event fs/notify/fsnotify.c:310 [inline]
                      send_to_group fs/notify/fsnotify.c:364 [inline]
                      fsnotify+0xc27/0x1050 fs/notify/fsnotify.c:541
                      fsnotify_parent include/linux/fsnotify.h:71 [inline]
                      fsnotify_file include/linux/fsnotify.h:90 [inline]
                      fsnotify_open include/linux/fsnotify.h:268 [inline]
                      do_sys_openat2+0x3a3/0x420 fs/open.c:1209
                      do_sys_open fs/open.c:1220 [inline]
                      __do_sys_open fs/open.c:1228 [inline]
                      __se_sys_open fs/open.c:1224 [inline]
                      __x64_sys_open+0x119/0x1c0 fs/open.c:1224
                      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
    INITIAL USE at:
                     lock_acquire kernel/locking/lockdep.c:5625 [inline]
                     lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline]
                     _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:311
                     fasync_remove_entry+0xb6/0x1f0 fs/fcntl.c:890
                     fasync_helper+0x9e/0xb0 fs/fcntl.c:993
                     fsnotify_fasync+0x4d/0x80 fs/notify/group.c:162
                     __fput+0x712/0x920 fs/file_table.c:277
                     task_work_run+0xdd/0x1a0 kernel/task_work.c:164
                     exit_task_work include/linux/task_work.h:32 [inline]
                     do_exit+0xbd4/0x2a60 kernel/exit.c:825
                     do_group_exit+0x125/0x310 kernel/exit.c:922
                     get_signal+0x47f/0x2160 kernel/signal.c:2808
                     arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
                     handle_signal_work kernel/entry/common.c:148 [inline]
                     exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
                     exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
                     __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
                     syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
                     do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
                     entry_SYSCALL_64_after_hwframe+0x44/0xae
    INITIAL READ USE at:
                          lock_acquire kernel/locking/lockdep.c:5625 [inline]
                          lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
                          __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
                          _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
                          kill_fasync_rcu fs/fcntl.c:1012 [inline]
                          kill_fasync fs/fcntl.c:1033 [inline]
                          kill_fasync+0x132/0x460 fs/fcntl.c:1026
                          snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387
                          snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516
                          snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578
                          snd_timer_start sound/core/timer.c:697 [inline]
                          snd_timer_start sound/core/timer.c:690 [inline]
                          snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985
                          __snd_timer_user_ioctl.isra.0+0xda8/0x24c0 sound/core/timer.c:2108
                          snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129
                          vfs_ioctl fs/ioctl.c:51 [inline]
                          __do_sys_ioctl fs/ioctl.c:1069 [inline]
                          __se_sys_ioctl fs/ioctl.c:1055 [inline]
                          __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
                          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
  }
  ... key      at: [<ffffffff90293100>] __key.0+0x0/0x40
  ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
   _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223
   kill_fasync_rcu fs/fcntl.c:1012 [inline]
   kill_fasync fs/fcntl.c:1033 [inline]
   kill_fasync+0x132/0x460 fs/fcntl.c:1026
   snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387
   snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516
   snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578
   snd_timer_start sound/core/timer.c:697 [inline]
   snd_timer_start sound/core/timer.c:690 [inline]
   snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985
   __snd_timer_user_ioctl.isra.0+0xda8/0x24c0 sound/core/timer.c:2108
   snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:1069 [inline]
   __se_sys_ioctl fs/ioctl.c:1055 [inline]
   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
   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

-> (&timer->lock){..-.}-{2:2} {
   IN-SOFTIRQ-W at:
                    lock_acquire kernel/locking/lockdep.c:5625 [inline]
                    lock_acquire+0x1ab/0x510 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:159
                    snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857
                    snd_timer_interrupt sound/core/timer.c:1155 [inline]
                    snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155
                    call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
                    expire_timers kernel/time/timer.c:1466 [inline]
                    __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
                    __run_timers kernel/time/timer.c:1715 [inline]
                    run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
                    __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
                    invoke_softirq kernel/softirq.c:432 [inline]
                    __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
                    irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
                    sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
                    asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
                    stack_trace_consume_entry+0x8f/0x160 kernel/stacktrace.c:88
                    arch_stack_walk+0x6d/0xe0 arch/x86/kernel/stacktrace.c:27
                    stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
                    save_stack+0x151/0x1e0 mm/page_owner.c:119
                    __set_page_owner+0x50/0x290 mm/page_owner.c:181
                    prep_new_page mm/page_alloc.c:2436 [inline]
                    get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4168
                    __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5390
                    alloc_pages_vma+0xd9/0x710 mm/mempolicy.c:2208
                    wp_page_copy+0x1bf/0x2450 mm/memory.c:3003
                    do_wp_page+0x2cb/0x1ad0 mm/memory.c:3313
                    handle_pte_fault mm/memory.c:4576 [inline]
                    __handle_mm_fault+0x2ada/0x5320 mm/memory.c:4693
                    handle_mm_fault+0x1c8/0x790 mm/memory.c:4791
                    do_user_addr_fault+0x48b/0x11c0 arch/x86/mm/fault.c:1390
                    handle_page_fault arch/x86/mm/fault.c:1475 [inline]
                    exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531
                    asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568
                    __put_user_nocheck_4+0x3/0x11
                    schedule_tail+0xaa/0xd0 kernel/sched/core.c:4635
                    ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:280
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5625 [inline]
                   lock_acquire+0x1ab/0x510 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:159
                   snd_timer_resolution+0x55/0x100 sound/core/timer.c:489
                   snd_timer_user_params.isra.0+0x18e/0x8c0 sound/core/timer.c:1852
                   __snd_timer_user_ioctl.isra.0+0x1020/0x24c0 sound/core/timer.c:2101
                   snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129
                   vfs_ioctl fs/ioctl.c:51 [inline]
                   __do_sys_ioctl fs/ioctl.c:1069 [inline]
                   __se_sys_ioctl fs/ioctl.c:1055 [inline]
                   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
                   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
 }
 ... key      at: [<ffffffff90592260>] __key.12+0x0/0x40
 ... acquired at:
   mark_usage kernel/locking/lockdep.c:4488 [inline]
   __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4969
   lock_acquire kernel/locking/lockdep.c:5625 [inline]
   lock_acquire+0x1ab/0x510 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:159
   snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857
   snd_timer_interrupt sound/core/timer.c:1155 [inline]
   snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155
   call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
   expire_timers kernel/time/timer.c:1466 [inline]
   __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
   __run_timers kernel/time/timer.c:1715 [inline]
   run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
   __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
   invoke_softirq kernel/softirq.c:432 [inline]
   __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
   irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
   sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
   asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
   stack_trace_consume_entry+0x8f/0x160 kernel/stacktrace.c:88
   arch_stack_walk+0x6d/0xe0 arch/x86/kernel/stacktrace.c:27
   stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
   save_stack+0x151/0x1e0 mm/page_owner.c:119
   __set_page_owner+0x50/0x290 mm/page_owner.c:181
   prep_new_page mm/page_alloc.c:2436 [inline]
   get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4168
   __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5390
   alloc_pages_vma+0xd9/0x710 mm/mempolicy.c:2208
   wp_page_copy+0x1bf/0x2450 mm/memory.c:3003
   do_wp_page+0x2cb/0x1ad0 mm/memory.c:3313
   handle_pte_fault mm/memory.c:4576 [inline]
   __handle_mm_fault+0x2ada/0x5320 mm/memory.c:4693
   handle_mm_fault+0x1c8/0x790 mm/memory.c:4791
   do_user_addr_fault+0x48b/0x11c0 arch/x86/mm/fault.c:1390
   handle_page_fault arch/x86/mm/fault.c:1475 [inline]
   exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531
   asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568
   __put_user_nocheck_4+0x3/0x11
   schedule_tail+0xaa/0xd0 kernel/sched/core.c:4635
   ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:280


stack backtrace:
CPU: 0 PID: 11611 Comm: syz-executor264 Not tainted 5.14.0-syzkaller #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:105
 print_irq_inversion_bug kernel/locking/lockdep.c:203 [inline]
 check_usage_forwards kernel/locking/lockdep.c:4031 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4163 [inline]
 mark_lock.cold+0x86/0x8e kernel/locking/lockdep.c:4593
 mark_usage kernel/locking/lockdep.c:4488 [inline]
 __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4969
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 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:159
 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857
 snd_timer_interrupt sound/core/timer.c:1155 [inline]
 snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:stack_trace_consume_entry+0x8f/0x160 kernel/stacktrace.c:88
Code: 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 90 00 00 00 <8b> 43 0c 85 c0 75 53 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1
RSP: 0018:ffffc9000c707500 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffffc9000c7075d8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff89400a6e RDI: ffffc9000c7075e4
RBP: 0000000000000009 R08: ffffffff8e7c89c8 R09: 0000000000000001
R10: fffff520018e0eaf R11: 0000000000086088 R12: ffffc9000c7075d8
R13: 0000000000000000 R14: ffff88801dcb8000 R15: 0000000000000000
 arch_stack_walk+0x6d/0xe0 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
 save_stack+0x151/0x1e0 mm/page_owner.c:119
 __set_page_owner+0x50/0x290 mm/page_owner.c:181
 prep_new_page mm/page_alloc.c:2436 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4168
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5390
 alloc_pages_vma+0xd9/0x710 mm/mempolicy.c:2208
 wp_page_copy+0x1bf/0x2450 mm/memory.c:3003
 do_wp_page+0x2cb/0x1ad0 mm/memory.c:3313
 handle_pte_fault mm/memory.c:4576 [inline]
 __handle_mm_fault+0x2ada/0x5320 mm/memory.c:4693
 handle_mm_fault+0x1c8/0x790 mm/memory.c:4791
 do_user_addr_fault+0x48b/0x11c0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568
RIP: 0010:__put_user_nocheck_4+0x3/0x11
Code: 00 00 48 39 d9 73 54 0f 1f 00 66 89 01 31 c9 0f 1f 00 c3 0f 1f 44 00 00 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 1f 00 <89> 01 31 c9 0f 1f 00 c3 66 0f 1f 44 00 00 48 bb f9 ef ff ff ff 7f
RSP: 0018:ffffc9000c707f38 EFLAGS: 00010293
RAX: 0000000000002d5b RBX: 00007fffffffeffd RCX: 0000000000f215d0
RDX: 1ffff11003b9713c RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000f215d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 schedule_tail+0xaa/0xd0 kernel/sched/core.c:4635
 ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:280
----------------
Code disassembly (best guess):
   0:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   7:	fc ff df
   a:	48 89 fa             	mov    %rdi,%rdx
   d:	48 c1 ea 03          	shr    $0x3,%rdx
  11:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
  15:	48 89 f8             	mov    %rdi,%rax
  18:	83 e0 07             	and    $0x7,%eax
  1b:	83 c0 03             	add    $0x3,%eax
  1e:	38 d0                	cmp    %dl,%al
  20:	7c 08                	jl     0x2a
  22:	84 d2                	test   %dl,%dl
  24:	0f 85 90 00 00 00    	jne    0xba
* 2a:	8b 43 0c             	mov    0xc(%rbx),%eax <-- trapping instruction
  2d:	85 c0                	test   %eax,%eax
  2f:	75 53                	jne    0x84
  31:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  38:	fc ff df
  3b:	48 89 da             	mov    %rbx,%rdx
  3e:	48                   	rex.W
  3f:	c1                   	.byte 0xc1

Crashes (41):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-kasan-gce 2021/08/30 20:50 upstream 7d2a07b76933 8f58a0ef .config console log report syz C possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/07/24 20:36 upstream f0fddcec6b62 4d1b57d4 .config console log report syz C possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/07/24 20:39 upstream f0fddcec6b62 4d1b57d4 .config console log report syz possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/11/02 17:54 upstream cc0356d6a02e 17f3edd2 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/11/02 15:05 upstream bfc484fe6abb 098b5d53 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/10/30 18:35 upstream 119c85055d86 098b5d53 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/10/27 20:34 upstream 1fc596a56b33 373bf66b .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/10/22 21:21 upstream 64222515138e 282f03fb .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/10/12 08:18 upstream fa5878760579 838e7e2c .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/10/12 07:39 upstream fa5878760579 838e7e2c .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/10/11 11:36 upstream 64570fbc14f8 838e7e2c .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/10/04 19:14 upstream 84b3e42564ac ce697b49 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/10/03 23:46 upstream 6761a0ae9895 db0f5787 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/10/02 20:28 upstream ab2a7a35c4e7 db0f5787 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/10/01 05:45 upstream 4de593fb965f 1d849ab4 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/09/22 04:35 upstream 92477dd1faa6 169724fe .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/09/16 02:42 upstream b7213ffa0e58 07e953c1 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce 2021/08/31 10:39 upstream 7d2a07b76933 8f58a0ef .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/08/26 12:01 upstream 73f3af7b4611 b599f2fc .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/08/24 21:18 upstream 6e764bcd1cf7 b599f2fc .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/08/23 17:26 upstream e22ce8eb631b b599f2fc .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/08/23 17:25 upstream e22ce8eb631b b599f2fc .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce 2021/08/21 07:23 upstream fa54d366a6e4 b599f2fc .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce 2021/08/16 07:30 upstream 7c60610d4767 2489ab88 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/08/16 07:26 upstream 7c60610d4767 2489ab88 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/08/16 07:16 upstream 7c60610d4767 2489ab88 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/08/07 16:30 upstream c9194f32bfd9 6972b106 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/08/06 05:14 upstream 902e7f373fff d2d6e680 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/08/04 21:48 upstream 251a1524293d b97d64c9 .config console log report info possible deadlock in snd_timer_interrupt
ci-qemu-upstream 2021/08/03 05:27 upstream c500bee1c5b2 6c236867 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/08/03 05:21 upstream c500bee1c5b2 6c236867 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce 2021/08/03 05:15 upstream c500bee1c5b2 6c236867 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/07/31 14:48 upstream c7d102232649 6c236867 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/07/30 19:48 upstream 764a5bc89b12 6c236867 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-root 2021/07/30 03:36 upstream 7e96bf476270 c585c7b0 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-smack-root 2021/07/30 03:12 upstream 7e96bf476270 c585c7b0 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/07/24 19:40 upstream f0fddcec6b62 4d1b57d4 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce-selinux-root 2021/07/24 19:40 upstream f0fddcec6b62 4d1b57d4 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-kasan-gce 2021/07/21 12:36 upstream 8cae8cd89f05 1b201b48 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-linux-next-kasan-gce-root 2021/09/15 06:43 linux-next 70ced02f322f 07e953c1 .config console log report info possible deadlock in snd_timer_interrupt
ci-upstream-linux-next-kasan-gce-root 2021/09/06 17:47 linux-next c1b13fe76e95 6ca60148 .config console log report info possible deadlock in snd_timer_interrupt
* Struck through repros no longer work on HEAD.