syzbot


INFO: rcu detected stall in memcpy

Status: fixed on 2018/02/14 17:52
Subsystems: sound
[Documentation on labels]
Reported-by: syzbot+387f48da65cb522abfe8@syzkaller.appspotmail.com
Fix commit: 29159a4ed704 ALSA: pcm: Abort properly at pending signal in OSS read/write loops
First crash: 2391d, last: 2386d
Duplicate bugs (1)
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
INFO: rcu detected stall in mulaw_decode sound 57 2386d 2390d 0/27 closed as dup on 2018/01/07 11:33
Discussions (1)
Title Replies (including bot) Last reply
Re: INFO: rcu detected stall in memcpy 8 (8) 2018/02/14 15:05

Sample crash report:
INFO: rcu_sched detected stalls on CPUs/tasks:
	(detected by 0, t=125002 jiffies, g=15654, c=15653, q=133)
All QSes seen, last rcu_sched kthread activity 125002 (4294863411-4294738409), jiffies_till_next_fqs=3, root ->qsmask 0x0
syz-executor1   R  running task    24936 11943   3739 0x0000000c
Call Trace:
 <IRQ>
 sched_show_task+0x4a3/0x5e0 kernel/sched/core.c:5198
 print_other_cpu_stall+0x996/0x1090 kernel/rcu/tree.c:1564
 check_cpu_stall.isra.61+0x6e6/0x15b0 kernel/rcu/tree.c:1682
 __rcu_pending kernel/rcu/tree.c:3440 [inline]
 rcu_pending kernel/rcu/tree.c:3502 [inline]
 rcu_check_callbacks+0x256/0xd00 kernel/rcu/tree.c:2842
 update_process_times+0x30/0x60 kernel/time/timer.c:1628
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162
 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1194
 __run_hrtimer kernel/time/hrtimer.c:1211 [inline]
 __hrtimer_run_queues+0x358/0xe20 kernel/time/hrtimer.c:1275
 hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1309
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:920
 </IRQ>
RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:30 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/kasan.c:210 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/kasan.c:241 [inline]
RIP: 0010:check_memory_region_inline mm/kasan/kasan.c:257 [inline]
RIP: 0010:check_memory_region+0x38/0x190 mm/kasan/kasan.c:267
RSP: 0000:ffff8801bd2ff868 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff11
RAX: ffff7fffffffffff RBX: ffffc9000160020b RCX: ffffffff841fceaf
RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffffc9000160020a
RBP: ffff8801bd2ff878 R08: ffffc9000160020a R09: dffffc0000000000
R10: 0000000000000001 R11: ffffed0037a5ff2e R12: ffffc9000160020a
R13: ffff8801bd2ff970 R14: dffffc0000000000 R15: ffffc9000160020a
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:344 [inline]
 cvt_s16_to_native sound/core/oss/mulaw.c:164 [inline]
 mulaw_decode+0x52f/0x770 sound/core/oss/mulaw.c:195
 mulaw_transfer+0x222/0x270 sound/core/oss/mulaw.c:273
 snd_pcm_plug_write_transfer+0x22d/0x420 sound/core/oss/pcm_plugin.c:611
 snd_pcm_oss_write2+0x260/0x420 sound/core/oss/pcm_oss.c:1311
 snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1372 [inline]
 snd_pcm_oss_write+0x5fe/0x830 sound/core/oss/pcm_oss.c:2646
 __vfs_write+0xef/0x970 fs/read_write.c:480
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007fa354a13c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: cccccccccccccccd RCX: 0000000000452ac9
RDX: 00000000fffffeb2 RSI: 0000000020083fc6 RDI: 0000000000000014
RBP: 00000000000005b5 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6998
R13: 00000000ffffffff R14: 00007fa354a146d4 R15: 0000000000000000
rcu_sched kthread starved for 125002 jiffies! g15654 c15653 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_sched       R  running task    23456     8      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2799 [inline]
 __schedule+0x8eb/0x2060 kernel/sched/core.c:3375
 schedule+0xf5/0x430 kernel/sched/core.c:3434
 schedule_timeout+0x118/0x230 kernel/time/timer.c:1793
 rcu_gp_kthread+0x9e5/0x1930 kernel/rcu/tree.c:2314
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/01/03 11:24 upstream 30a7acd57389 00193447 .config console log report ci-upstream-kasan-gce
2018/01/08 06:44 mmots 69eed2290e1d 19c05fff .config console log report ci-upstream-mmots-kasan-gce
2018/01/08 04:42 mmots 69eed2290e1d 19c05fff .config console log report ci-upstream-mmots-kasan-gce
2018/01/07 21:48 mmots 69eed2290e1d 19c05fff .config console log report ci-upstream-mmots-kasan-gce
2018/01/06 19:22 linux-next 990b6a07d18c 053171ea .config console log report ci-upstream-next-kasan-gce
2018/01/06 16:18 mmots 69eed2290e1d 053171ea .config console log report ci-upstream-mmots-kasan-gce
2018/01/05 23:04 linux-next 990b6a07d18c 00193447 .config console log report ci-upstream-next-kasan-gce
2018/01/05 16:40 mmots ad036b63ee57 00193447 .config console log report ci-upstream-mmots-kasan-gce
2018/01/05 14:45 mmots ad036b63ee57 00193447 .config console log report ci-upstream-mmots-kasan-gce
2018/01/05 00:53 linux-next 73005e1a35fd 00193447 .config console log report ci-upstream-next-kasan-gce
2018/01/04 22:05 mmots ad036b63ee57 00193447 .config console log report ci-upstream-mmots-kasan-gce
2018/01/04 13:33 mmots ad036b63ee57 00193447 .config console log report ci-upstream-mmots-kasan-gce
* Struck through repros no longer work on HEAD.