syzbot


INFO: rcu detected stall in snd_pcm_oss_read

Status: fixed on 2019/03/06 07:43
Subsystems: sound
[Documentation on labels]
Reported-by: syzbot+fbe0496f92a0ce7b786c@syzkaller.appspotmail.com
Fix commit: e190161f96b8 ALSA: pcm: Fix tight loop of OSS capture stream
First crash: 1948d, last: 1948d
Discussions (3)
Title Replies (including bot) Last reply
[PATCH AUTOSEL 4.19 001/167] drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse" 195 (195) 2019/09/15 15:19
[PATCH 4.20 00/80] 4.20.7-stable review 84 (84) 2019/02/05 14:43
INFO: rcu detected stall in snd_pcm_oss_read 0 (1) 2018/12/24 15:24
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: rcu detected stall in snd_pcm_oss_read 1 1451d 1451d 0/1 auto-closed as invalid on 2020/09/01 05:31
upstream INFO: rcu detected stall in snd_pcm_oss_read (2) sound 1 251d 251d 0/26 auto-obsoleted due to no activity on 2023/11/15 07:39

Sample crash report:
hrtimer: interrupt took 35234 ns
audit: type=1400 audit(1545621421.464:37): avc:  denied  { map } for  pid=6182 comm="sh" path="/bin/dash" dev="sda1" ino=1473 scontext=system_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (13423 ticks this GP) idle=6c6/1/0x4000000000000002 softirq=7663/7665 fqs=5214 
rcu: 	 (t=10500 jiffies g=5229 q=6)
NMI backtrace for cpu 0
CPU: 0 PID: 6180 Comm: syz-executor053 Not tainted 4.20.0-rc7+ #165
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+0x1d3/0x2c6 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1c2/0x22c 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:164 [inline]
 rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree.c:1195
 print_cpu_stall.cold.65+0x1f3/0x3c6 kernel/rcu/tree.c:1334
 check_cpu_stall kernel/rcu/tree.c:1408 [inline]
 rcu_pending kernel/rcu/tree.c:2961 [inline]
 rcu_check_callbacks+0xac1/0x1410 kernel/rcu/tree.c:2506
 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+0x41c/0x10d0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline]
 smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:__raw_read_unlock_irq include/linux/rwlock_api_smp.h:244 [inline]
RIP: 0010:_raw_read_unlock_irq+0x56/0x80 kernel/locking/spinlock.c:264
Code: 52 89 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 32 48 83 3d 33 94 7a 01 00 74 1f fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 d0 c2 7d f9 65 8b 05 69 80 2a 78 85 c0 74 05 5b
RSP: 0018:ffff8881be89f660 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffffffff89e89e60 RCX: 1ffff11039b689cc
RDX: 1ffffffff12a4030 RSI: 0000000000000000 RDI: ffffffff89520180
RBP: ffff8881be89f668 R08: ffff8881cdb44e60 R09: 0000000000000006
R10: 0000000000000000 R11: ffff8881cdb445c0 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8881be89f828
 __snd_pcm_stream_unlock_mode+0x125/0x150 sound/core/pcm_native.c:145
 snd_pcm_stream_unlock_irq sound/core/pcm_native.c:202 [inline]
 snd_pcm_delay+0x234/0x380 sound/core/pcm_native.c:2698
 snd_pcm_kernel_ioctl+0x1e0/0x220 sound/core/pcm_native.c:2998
 snd_pcm_oss_capture_position_fixup+0x1a1/0x250 sound/core/oss/pcm_oss.c:1202
 snd_pcm_oss_read3+0x181/0x410 sound/core/oss/pcm_oss.c:1271
 io_capture_transfer+0x27d/0x310 sound/core/oss/io.c:73
 snd_pcm_plug_read_transfer+0x1d7/0x3b0 sound/core/oss/pcm_plugin.c:651
 snd_pcm_oss_read2+0x221/0x450 sound/core/oss/pcm_oss.c:1474
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1512 [inline]
 snd_pcm_oss_read+0x4e4/0x820 sound/core/oss/pcm_oss.c:2752
 __vfs_read+0x117/0x9b0 fs/read_write.c:416
 vfs_read+0x17f/0x3c0 fs/read_write.c:452
 ksys_read+0x101/0x260 fs/read_write.c:578
 __do_sys_read fs/read_write.c:588 [inline]
 __se_sys_read fs/read_write.c:586 [inline]
 __x64_sys_read+0x73/0xb0 fs/read_write.c:586
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443ef9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 7b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffd155a428 EFLAGS: 00000217 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000443ef9
RDX: 0000000000000008 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00000000006ce018 R08: 00000000004002e0 R09: 00000000004002e0
R10: 00000000004002e0 R11: 0000000000000217 R12: 0000000000401c00
R13: 0000000000401c90 R14: 0000000000000000 R15: 0000000000000000
sched: RT throttling activated

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/12/24 03:22 upstream 3c730b1041ae e3bd7ab8 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2018/12/24 00:47 upstream 3c730b1041ae e3bd7ab8 .config console log report ci-upstream-kasan-gce-selinux-root
* Struck through repros no longer work on HEAD.