On Sun, 07 Jan 2018 12:33:05 +0100, Dmitry Vyukov wrote: > > On Thu, Jan 4, 2018 at 2:57 PM, syzbot > <syzbot+ebf0a29fce8f37153f57@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > > > syzkaller hit the following crash on > > ad036b63ee57df9ab802a4eb20cbbbec66aa4520 > > git://git.cmpxchg.org/linux-mmots.git/master > > compiler: gcc (GCC) 7.1.1 20170620 > > .config is attached > > Raw console output is attached. > > Unfortunately, I don't have any reproducer for this bug yet. > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+ebf0a29fce8f37153f57@xxxxxxxxxxxxxxxxxxxxxxxxx > > It will help syzbot understand when the bug is fixed. See footer for > > details. > > If you forward the report, please keep this part and the footer. > > > > INFO: rcu_sched self-detected stall on CPU > > 1-....: (124999 ticks this GP) idle=71e/1/4611686018427387906 > > softirq=9229/9229 fqs=31218 > > (t=125000 jiffies g=4571 c=4570 q=876) > > NMI backtrace for cpu 1 > > CPU: 1 PID: 4500 Comm: syz-executor6 Not tainted 4.15.0-rc6-mm1+ #50 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > Call Trace: > > <IRQ> > > __dump_stack lib/dump_stack.c:17 [inline] > > dump_stack+0x137/0x198 lib/dump_stack.c:53 > > nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 > > nmi_trigger_cpumask_backtrace+0x122/0x180 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:156 [inline] > > rcu_dump_cpu_stacks+0x186/0x1d7 kernel/rcu/tree.c:1375 > > print_cpu_stall kernel/rcu/tree.c:1524 [inline] > > check_cpu_stall kernel/rcu/tree.c:1592 [inline] > > __rcu_pending kernel/rcu/tree.c:3362 [inline] > > rcu_pending kernel/rcu/tree.c:3424 [inline] > > rcu_check_callbacks+0x1a64/0x1de0 kernel/rcu/tree.c:2764 > > 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:1176 > > __run_hrtimer kernel/time/hrtimer.c:1210 [inline] > > __hrtimer_run_queues+0x2c8/0xb50 kernel/time/hrtimer.c:1274 > > hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1308 > > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] > > smp_apic_timer_interrupt+0xc9/0x4c0 arch/x86/kernel/apic/apic.c:1050 > > apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:920 > > </IRQ> > > RIP: 0010:__memcpy+0x0/0x20 > > RSP: 0018:ffff8801cd597918 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11 > > RAX: fffff52000255558 RBX: 0000000000000002 RCX: ffffffff83b7d25e > > RDX: 0000000000000002 RSI: ffff8801cd597a00 RDI: ffffc900012aaab8 > > RBP: ffff8801cd597938 R08: fffff52000255558 R09: fffff52000255558 > > R10: 0000000000000001 R11: fffff52000255557 R12: ffffc900012aaab8 > > R13: ffff8801cd597a00 R14: ffff8801d0e45000 R15: dffffc0000000000 > > memcpy include/linux/string.h:344 [inline] > > cvt_s16_to_native sound/core/oss/mulaw.c:164 [inline] > > mulaw_decode+0x50e/0x740 sound/core/oss/mulaw.c:195 > > mulaw_transfer+0x222/0x270 sound/core/oss/mulaw.c:273 > > snd_pcm_plug_write_transfer+0x20b/0x390 sound/core/oss/pcm_plugin.c:611 > > snd_pcm_oss_write2+0x22e/0x3c0 sound/core/oss/pcm_oss.c:1311 > > snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1372 [inline] > > snd_pcm_oss_write+0x4c1/0x690 sound/core/oss/pcm_oss.c:2646 > > __vfs_write+0xef/0x740 fs/read_write.c:480 > > vfs_write+0x189/0x510 fs/read_write.c:544 > > SYSC_write fs/read_write.c:589 [inline] > > SyS_write+0xd4/0x1a0 fs/read_write.c:581 > > entry_SYSCALL_64_fastpath+0x23/0x9a > > RIP: 0033:0x452ac9 > > RSP: 002b:00007febc940bc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 > > RAX: ffffffffffffffda RBX: 000000000071bf58 RCX: 0000000000452ac9 > > RDX: 00000000ffffffa2 RSI: 0000000020001000 RDI: 0000000000000013 > > RBP: 0000000000000521 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5bb8 > > R13: 00000000ffffffff R14: 00007febc940c6d4 R15: 000000000000000b > > > +ALSA maintainers > > This looks like: > > #syz dup: INFO: rcu detected stall in memcpy > > right? Yes, very likely. And I found that this is a different issue from the recently fixed aloop bug. It's been already nailed down, and I'll submit / merge the fixes soon. Hopefully they'll be included in 4.15-rc8. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
