syzbot


INFO: task hung in ctrl_cdev_ioctl
Status: upstream: reported syz repro on 2020/01/10 23:24
Reported-by: syzbot+12eda31c0851e1cdabf4@syzkaller.appspotmail.com
First crash: 868d, last: 728d

Cause bisection: failed (bisect log)

Fix bisection: failed (bisect log)
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in ctrl_cdev_ioctl 1 683d 683d 0/1 auto-closed as invalid on 2020/11/09 06:21

Sample crash report:
INFO: task syz-executor.5:15593 blocked for more than 143 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28360 15593  10978 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: Bad RIP value.
RSP: 002b:00007fc180a29c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc180a2a6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.1:15607 blocked for more than 143 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28360 15607  10974 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007f80452adc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f80452ae6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.1:15613 blocked for more than 143 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28360 15613  10974 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007f804528cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f804528d6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000004
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.1:15623 blocked for more than 144 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28360 15623  10974 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007f804526bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f804526c6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076c06c
INFO: task syz-executor.2:15603 blocked for more than 144 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28360 15603  10970 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007f4ac5adec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4ac5adf6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.2:15610 blocked for more than 144 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28360 15610  10970 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007f4ac5abdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4ac5abe6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000004
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.2:15621 blocked for more than 144 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28360 15621  10970 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007f4ac5a9cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4ac5a9d6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076c06c
INFO: task syz-executor.0:15600 blocked for more than 144 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28360 15600  10976 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
 kthread_stop+0x187/0x800 kernel/kthread.c:559
 ubi_detach_mtd_dev+0x219/0x43a drivers/mtd/ubi/build.c:1101
 ctrl_cdev_ioctl+0x1d6/0x2d0 drivers/mtd/ubi/cdev.c:1068
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007fde4ac43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fde4ac446d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.0:15608 blocked for more than 145 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28360 15608  10976 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007fde4ac22c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fde4ac236d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000004
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.0:15618 blocked for more than 145 seconds.
      Not tainted 5.6.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28360 15618  10976 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 48 8b 5c 24 30 48 01 d8 48 89 04 24 48 89 4c 24 08 e8 db 67 fa ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 06 7c ce 48 <89> 4c 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 84 b4 ff ff eb 92 cc
RSP: 002b:00007fde4ac01c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fde4ac026d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000003
RBP: 000000000076c060 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076c06c

Showing all locks held in the system:
3 locks held by kworker/u4:7/568:
 #0: ffff8880ae937558 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline]
 #0: ffff8880ae937558 (&rq->lock){-.-.}, at: __schedule+0x232/0x1f90 kernel/sched/core.c:4028
 #1: ffffffff89bac280 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5747
 #2: ffff8880ae927418 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:936
1 lock held by khungtaskd/1120:
 #0: ffffffff89bac280 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333
1 lock held by rsyslogd/10796:
 #0: ffff88809f04e8e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821
2 locks held by getty/10918:
 #0: ffff88809e861090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc900017fb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/10919:
 #0: ffff888095911090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000188b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/10920:
 #0: ffff888086e96090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000187b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/10921:
 #0: ffff8880a709e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000186b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/10922:
 #0: ffff88809d751090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000182b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/10923:
 #0: ffff888091692090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc9000185b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
2 locks held by getty/10924:
 #0: ffff8880a698b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340
 #1: ffffc900017cb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.5/15593:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.1/15607:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.1/15613:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.1/15623:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.2/15603:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.2/15610:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.2/15621:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.0/15600:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.0/15608:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.0/15618:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.4/15601:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.4/15609:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.4/15617:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.3/15611:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.3/15614:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.3/15625:
 #0: ffffffff8a330800 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1067

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

NMI backtrace for cpu 0
CPU: 0 PID: 1120 Comm: khungtaskd Not tainted 5.6.0-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+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xb11/0x10c0 kernel/hung_task.c:289
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2020/02/26 16:07 upstream f8788d86ab28 59b57593 .config log report syz
ci-upstream-kasan-gce-selinux-root 2020/02/25 00:32 upstream f8788d86ab28 59b57593 .config log report syz
ci-upstream-kasan-gce-root 2020/01/09 09:54 upstream b07f636fca1c ddc3e859 .config log report syz
ci-upstream-kasan-gce-root 2020/05/28 02:44 upstream b0c3ba31be3e 142a0957 .config log report