syzbot


INFO: task hung in misc_open

Status: auto-closed as invalid on 2019/04/20 12:01
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+d389fc3880aa60138006@syzkaller.appspotmail.com
First crash: 2128d, last: 2043d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in misc_open (2) kernel 8 1706d 1707d 0/26 auto-closed as invalid on 2019/12/23 14:44
upstream INFO: task hung in misc_open (4) usb C error inconclusive 144 486d 1198d 22/26 fixed on 2023/02/24 13:50
upstream INFO: task hung in misc_open (3) kernel 2 1413d 1421d 0/26 auto-closed as invalid on 2020/10/12 03:30

Sample crash report:
VFS: Can't find a Minix filesystem V1 | V2 | V3 on device loop4.
9pnet: p9_fd_create_unix (12354): problem connecting socket: ./file0: -111
INFO: task syz-executor7:12292 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D23560 12292   4433 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007fb895360c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb8953616d4 RCX: 0000000000456a09
RDX: 0000000000000002 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1c60 R14: 00000000004c7115 R15: 0000000000000001
INFO: task syz-executor7:12346 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D25208 12346   4433 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007fb8952fdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb8952fe6d4 RCX: 0000000000456a09
RDX: 0000000000000002 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 0000000000930320 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1c60 R14: 00000000004c7115 R15: 0000000000000004
INFO: task syz-executor0:12293 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D24808 12293   4428 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007fd535669c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd53566a6d4 RCX: 0000000000456a09
RDX: 0000000000000180 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d2068 R14: 00000000004c73bd R15: 0000000000000001
INFO: task syz-executor6:12300 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D23544 12300   4434 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007f8a95969c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8a9596a6d4 RCX: 0000000000456a09
RDX: 0000000000000002 RSI: 0000000020000540 RDI: ffffffffffffff9c
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1c60 R14: 00000000004c7115 R15: 0000000000000000
INFO: task syz-executor6:12306 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D25400 12306   4434 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007f8a95948c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8a959496d4 RCX: 0000000000456a09
RDX: 0000000000000002 RSI: 0000000020000540 RDI: ffffffffffffff9c
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1c60 R14: 00000000004c7115 R15: 0000000000000001
INFO: task syz-executor2:12302 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D22944 12302  11828 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007fac4b36fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fac4b3706d4 RCX: 0000000000456a09
RDX: 0000000000000842 RSI: 0000000020000400 RDI: ffffffffffffff9c
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d2068 R14: 00000000004c73bd R15: 0000000000000000
INFO: task syz-executor2:12351 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D25400 12351  11828 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007fac4b32dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fac4b32e6d4 RCX: 0000000000456a09
RDX: 0000000000000842 RSI: 0000000020000400 RDI: ffffffffffffff9c
RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d2068 R14: 00000000004c73bd R15: 0000000000000002
INFO: task syz-executor3:12311 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D24200 12311   4435 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007f3eb2cbac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3eb2cbb6d4 RCX: 0000000000456a09
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1ae0 R14: 00000000004c7024 R15: 0000000000000000
INFO: task syz-executor3:12315 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D24640 12315   4435 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007f3eb2c99c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3eb2c9a6d4 RCX: 0000000000456a09
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1ae0 R14: 00000000004c7024 R15: 0000000000000001
INFO: task syz-executor4:12331 blocked for more than 140 seconds.
      Not tainted 4.18.0-rc6+ #168
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D23560 12331   4429 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2853 [inline]
 __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501
 schedule+0xfb/0x450 kernel/sched/core.c:3545
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603
 __mutex_lock_common kernel/locking/mutex.c:834 [inline]
 __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909
 misc_open+0x69/0x560 drivers/char/misc.c:107
 chrdev_open+0x25a/0x770 fs/char_dev.c:417
 do_dentry_open+0x818/0xe40 fs/open.c:794
 vfs_open+0x139/0x230 fs/open.c:908
 do_last fs/namei.c:3399 [inline]
 path_openat+0x174a/0x4e10 fs/namei.c:3540
 do_filp_open+0x255/0x380 fs/namei.c:3574
 do_sys_open+0x584/0x760 fs/open.c:1101
 __do_sys_openat fs/open.c:1128 [inline]
 __se_sys_openat fs/open.c:1122 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1122
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456a09
Code: 24 00 00 00 e8 e8 4e fd ff 0f 0b e8 c1 34 00 00 e9 3c ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 40 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 
RSP: 002b:00007fae84074c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fae840756d4 RCX: 0000000000456a09
RDX: 0000000000000002 RSI: 0000000020000100 RDI: ffffffffffffff9c
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d1c60 R14: 00000000004c7115 R15: 0000000000000000

Showing all locks held in the system:
1 lock held by khungtaskd/773:
 #0: 0000000001725924 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461
1 lock held by rsyslogd/4290:
2 locks held by getty/4380:
 #0: 00000000f0ac34a8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000aadd18a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4381:
 #0: 0000000013957cdc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000f0e999d7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4382:
 #0: 0000000076204aec (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 0000000027aeed79 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4383:
 #0: 00000000f5017fd8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000009ce314a5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4384:
 #0: 00000000eeb81650 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000006e271441 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4385:
 #0: 000000007095ebc3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000d8dc3c7c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4386:
 #0: 00000000971dc434 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000004f732e86 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
1 lock held by syz-executor7/12292:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor7/12346:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
3 locks held by syz-executor0/12288:
1 lock held by syz-executor0/12293:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor6/12300:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor6/12306:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor2/12302:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor2/12351:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor3/12311:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor3/12315:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor4/12331:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107
1 lock held by syz-executor4/12334:
 #0: 0000000061acdac8 (misc_mtx){+.+.}, at: misc_open+0x69/0x560 drivers/char/misc.c:107

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc6+ #168
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+0x1c9/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 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_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline]
 watchdog+0x9c4/0xf80 kernel/hung_task.c:252
 kthread+0x345/0x410 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/07/30 08:16 upstream 3cfb6772d4cf 1a381291 .config console log report ci-upstream-kasan-gce-root
2018/10/22 12:00 linux-next 8c60c36d0b8c ecb386fe .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.