INFO: rcu detected stall in snd_seq_write

Status: fixed on 2019/08/14 02:14
Subsystems: sound
[Documentation on labels]
Reported-by: syzbot+97aae04ce27e39cbfca9@syzkaller.appspotmail.com
Fix commit: ede34f397ddb ALSA: seq: Break too long mutex context in the write loop
First crash: 2892d, last: 2560d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ Discussions (10)
Title Replies (including bot) Last reply
[PATCH 3.16 00/47] 3.16.76-rc1 review 57 (57) 2019/11/02 07:39
[PATCH 4.9 000/223] 4.9.187-stable review 231 (231) 2019/08/28 03:02
[PATCH 5.2 000/413] 5.2.3-stable review 444 (444) 2019/08/05 12:40
[PATCH 4.4 000/158] 4.4.187-stable review 166 (166) 2019/08/03 15:57
[PATCH 4.14 000/293] 4.14.135-stable review 302 (302) 2019/07/31 09:35
[PATCH 4.19 000/271] 4.19.61-stable review 284 (284) 2019/07/27 10:51
[PATCH 5.1 000/371] 5.1.20-stable review 384 (384) 2019/07/26 12:24
Reminder: 4 open syzbot bugs in sound subsystem 1 (1) 2019/07/09 20:18
Reminder: 9 open syzbot bugs in sound subsystem 1 (1) 2019/06/24 05:07
INFO: rcu detected stall in snd_seq_write 1 (2) 2018/08/27 21:04
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in snd_seq_write (2) sound 1 syz done 21 1718d 1730d 20/29 fixed on 2022/03/08 16:11
linux-4.19 INFO: rcu detected stall in snd_seq_write 1 1 2419d 2419d 0/1 auto-closed as invalid on 2020/04/10 16:27

Sample crash report:
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 	0-....: (105000 ticks this GP) idle=2f6/1/0x4000000000000002 softirq=23001/23001 fqs=26239 
rcu: 	 (t=105008 jiffies g=49145 q=2382)
NMI backtrace for cpu 0
CPU: 0 PID: 8551 Comm: syz-executor7 Not tainted 4.18.0-next-20180824+ #47
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:162 [inline]
 rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
 print_cpu_stall.cold.78+0x2fb/0x59c kernel/rcu/tree.c:1478
 check_cpu_stall kernel/rcu/tree.c:1550 [inline]
 __rcu_pending kernel/rcu/tree.c:3276 [inline]
 rcu_pending kernel/rcu/tree.c:3319 [inline]
 rcu_check_callbacks+0xd4a/0x15a0 kernel/rcu/tree.c:2665
 update_process_times+0x2d/0x70 kernel/time/timer.c:1636
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3eb/0xff0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline]
 smp_apic_timer_interrupt+0x16d/0x6a0 arch/x86/kernel/apic/apic.c:1054
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:867
 </IRQ>
RIP: 0010:lock_release+0xa2/0x9f0 kernel/locking/lockdep.c:3910
Code: f2 c7 40 08 f2 f2 f2 f2 c7 40 0c 00 f2 f2 f2 c7 40 10 f2 f2 f2 f2 c7 40 14 00 f2 f2 f2 65 48 8b 04 25 28 00 00 00 48 89 45 d0 <31> c0 48 89 f8 48 c1 e8 03 0f b6 14 10 48 89 f8 83 e0 07 83 c0 03
RSP: 0018:ffff8801aa0078c8 EFLAGS: 00000292 ORIG_RAX: ffffffffffffff13
RAX: 2ec5cd2493d34200 RBX: 1ffff10035400f1e RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8801a9b56bbc
RBP: ffff8801aa0079f8 R08: 00000000000010df R09: 0000000000000001
R10: ffff8801a9b56be8 R11: 737c3e5c87308161 R12: ffff8801aa0079d0
R13: ffff8801c778d4c8 R14: ffff8801aa007ae0 R15: ffff8801a9b56380
 __might_fault+0x19e/0x1e0 mm/memory.c:4585
 _copy_from_user+0x30/0x150 lib/usercopy.c:10
 copy_from_user include/linux/uaccess.h:147 [inline]
 snd_seq_write+0x472/0x8d0 sound/core/seq/seq_clientmgr.c:1033
 __vfs_write+0x117/0x9d0 fs/read_write.c:485
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f09af65dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f09af65e6d4 RCX: 0000000000457089
RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d78a8 R14: 00000000004ca886 R15: 0000000000000000

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/08/26 18:47 linux-next e27bc174c9c6 758cd203 .config console log report syz ci-upstream-linux-next-kasan-gce-root
2019/07/24 11:42 upstream c6dd78fcb8ee 32329ceb .config console log report ci-upstream-kasan-gce-selinux-root
2019/07/24 07:06 upstream c6dd78fcb8ee de453f34 .config console log report ci-upstream-kasan-gce-root
2019/07/24 01:11 upstream c6dd78fcb8ee de453f34 .config console log report ci-upstream-kasan-gce-selinux-root
2019/07/23 15:56 upstream c6dd78fcb8ee de453f34 .config console log report ci-upstream-kasan-gce-smack-root
2019/07/23 13:48 upstream c6dd78fcb8ee de453f34 .config console log report ci-upstream-kasan-gce-selinux-root
2019/07/23 10:58 upstream c6dd78fcb8ee 55e0c077 .config console log report ci-upstream-kasan-gce-root
2019/07/23 03:07 upstream c6dd78fcb8ee 55e0c077 .config console log report ci-upstream-kasan-gce-selinux-root
2019/07/23 03:07 upstream c6dd78fcb8ee 55e0c077 .config console log report ci-upstream-kasan-gce-root
2019/07/22 07:29 upstream c6dd78fcb8ee b3c615f5 .config console log report ci-upstream-kasan-gce-root
2019/04/28 01:25 upstream 037904a22bf8 b617407b .config console log report ci-upstream-kasan-gce-smack-root
2019/04/25 01:58 upstream cd8dead0c394 8e3c52b1 .config console log report ci-upstream-kasan-gce-smack-root
2019/04/12 10:08 upstream 2d06b235815e 8916f5e1 .config console log report ci-upstream-kasan-gce-smack-root
2019/01/08 16:16 upstream 3bd6e94bec12 37dd2683 .config console log report ci-upstream-kasan-gce-root
2018/12/18 13:27 upstream 1a9430db2835 4edaba93 .config console log report ci-upstream-kasan-gce-root
2018/12/18 12:29 upstream 1a9430db2835 4edaba93 .config console log report ci-upstream-kasan-gce-root
2018/12/18 08:15 upstream 1a9430db2835 def91db3 .config console log report ci-upstream-kasan-gce-root
2018/12/14 14:13 linux-next d14b746c6c1c 7624ddd6 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.