On Sat, Nov 14, 2020 at 2:42 PM syzbot <syzbot+9dec836197fea6892a28@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: e7018751 usb: host: ehci-mxc: Remove the driver > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > console output: https://syzkaller.appspot.com/x/log.txt?x=15d0c6a1500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a84e3059298aeb27 > dashboard link: https://syzkaller.appspot.com/bug?extid=9dec836197fea6892a28 > compiler: gcc (GCC) 10.1.0-syz 20200507 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9dec836197fea6892a28@xxxxxxxxxxxxxxxxxxxxxxxxx It seems syzkaller has found another way to reboot the machine. systemd initialiated shutdown: [ [0;32m OK [0m] Stopped Raise network interfaces. but it's unclear why. Kernel also hanged: [ 2599.057387][ T1] systemd-shutdown[1]: Sending SIGTERM to remaining processes... [ 2599.704086][ T1] systemd-shutdown[1]: Sending SIGKILL to remaining processes... [ 2600.107613][ T1] systemd-shutdown[1]: All loop devices detached. [ 2746.006716][ T1253] INFO: task systemd-shutdow:1 blocked for more than 143 seconds. [ 2746.014884][ T1253] Not tainted 5.10.0-rc3-syzkaller #0 It seems due to some misbehaving device: [ 2746.057796][ T1253] schedule+0xcb/0x270 [ 2746.061900][ T1253] wait_for_device_probe+0x1be/0x220 [ 2746.089974][ T1253] device_shutdown+0x18/0x5c0 [ 2746.094669][ T1253] __do_sys_reboot.cold+0x5d/0x97 Most likely some USB device because there is lots of USB-related output before that. > INFO: task systemd-shutdow:1 blocked for more than 143 seconds. > Not tainted 5.10.0-rc3-syzkaller #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:systemd-shutdow state:D stack:23432 pid: 1 ppid: 0 flags:0x00000000 > Call Trace: > context_switch kernel/sched/core.c:3774 [inline] > __schedule+0x8a2/0x1f30 kernel/sched/core.c:4523 > schedule+0xcb/0x270 kernel/sched/core.c:4601 > wait_for_device_probe+0x1be/0x220 drivers/base/dd.c:702 > device_shutdown+0x18/0x5c0 drivers/base/core.c:4007 > kernel_restart_prepare kernel/reboot.c:76 [inline] > kernel_restart kernel/reboot.c:246 [inline] > __do_sys_reboot.cold+0x5d/0x97 kernel/reboot.c:347 > do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x7fa389e6c8c6 > Code: Unable to access opcode bytes at RIP 0x7fa389e6c89c. > RSP: 002b:00007ffe1fb46e18 EFLAGS: 00000206 ORIG_RAX: 00000000000000a9 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa389e6c8c6 > RDX: 0000000001234567 RSI: 0000000028121969 RDI: fffffffffee1dead > RBP: 00007ffe1fb46ea8 R08: 0000000000002800 R09: 0000000000000005 > R10: 0000000000000002 R11: 0000000000000206 R12: 0000000000000000 > R13: 0000000000000000 R14: 000055c2d05dc150 R15: 00007ffe1fb47198 > > Showing all locks held in the system: > 1 lock held by systemd-shutdow/1: > #0: ffffffff871288a8 (system_transition_mutex){+.+.}-{3:3}, at: __do_sys_reboot+0x1a4/0x3e0 kernel/reboot.c:344 > 5 locks held by kworker/1:0/17: > 1 lock held by khungtaskd/1253: > #0: ffffffff872492e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:6253 > > ============================================= > > NMI backtrace for cpu 1 > CPU: 1 PID: 1253 Comm: khungtaskd Not tainted 5.10.0-rc3-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x107/0x163 lib/dump_stack.c:118 > nmi_cpu_backtrace.cold+0x46/0xe0 lib/nmi_backtrace.c:105 > nmi_trigger_cpumask_backtrace+0x1da/0x200 lib/nmi_backtrace.c:62 > trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] > watchdog+0xd32/0xf70 kernel/hung_task.c:294 > kthread+0x38c/0x460 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 > Sending NMI from CPU 1 to CPUs 0: > NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] > NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] > NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] > NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:517 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000a923c105b411505f%40google.com.
