syzbot


INFO: task hung in ctrl_cdev_ioctl

Status: auto-closed as invalid on 2020/11/09 06:21
Reported-by: syzbot+69aa38ac3bcbf218af1f@syzkaller.appspotmail.com
First crash: 712d, last: 712d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in ctrl_cdev_ioctl syz error error 4 757d 895d 0/22 upstream: reported syz repro on 2020/01/10 23:24

Sample crash report:
ubi0: max/mean erase counter: 1/1, WL threshold: 4096, image sequence number: 3168473204
ubi0: available PEBs: 28, total reserved PEBs: 4, PEBs reserved for bad PEB handling: 0
ubi0: background thread "ubi_bgt0d" started, PID 4072
ubi0: detaching mtd0
INFO: task syz-executor.5:4061 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28896  4061   6359 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f00ac1efc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000006
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f00ac1f06d4
INFO: task syz-executor.4:4067 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28800  4067   6358 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f2dbbf91c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000007
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f2dbbf926d4
INFO: task syz-executor.4:4080 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D30080  4080   6358 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f2dbbf70c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000006
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f2dbbf716d4
INFO: task syz-executor.4:4081 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D30080  4081   6358 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f2dbbf4fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000006
RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f2dbbf506d4
INFO: task syz-executor.4:4094 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D29216  4094   6358 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f2dbbf2ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000007
RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f2dbbf2f6d4
INFO: task syz-executor.3:4063 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28832  4063   6357 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f275792cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000009
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f275792d6d4
INFO: task syz-executor.3:4070 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D30080  4070   6357 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f275790bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000004
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f275790c6d4
INFO: task syz-executor.3:4079 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28576  4079   6357 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f27578eac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000008
RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f27578eb6d4
INFO: task syz-executor.3:4083 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D30080  4083   6357 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f27578c9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000003
RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f27578ca6d4
INFO: task syz-executor.3:4087 blocked for more than 140 seconds.
      Not tainted 4.14.184-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D30096  4087   6357 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cba9
RSP: 002b:00007f27578a8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e2240 RCX: 000000000045cba9
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 0000000000000004
RBP: 000000000078c180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000215 R14: 00000000004c472a R15: 00007f27578a96d4

Showing all locks held in the system:
1 lock held by khungtaskd/1058:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8146c8d0>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by syz-executor.5/4061:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.4/4067:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.4/4080:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.4/4081:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.4/4094:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.3/4063:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.3/4070:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.3/4079:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.3/4083:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.3/4087:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.3/4089:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.1/4066:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.1/4078:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.1/4084:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.1/4085:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014
1 lock held by syz-executor.1/4086:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.2/4064:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.2/4075:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.0/4065:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe562>] ctrl_cdev_ioctl+0x142/0x220 drivers/mtd/ubi/cdev.c:1039
1 lock held by syz-executor.0/4068:
 #0:  (ubi_devices_mutex){+.+.}, at: [<ffffffff83cbe5b0>] ctrl_cdev_ioctl+0x190/0x220 drivers/mtd/ubi/cdev.c:1014

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

NMI backtrace for cpu 0
CPU: 0 PID: 1058 Comm: khungtaskd Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e2/0xb80 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff863e461e

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/07/12 06:20 linux-4.14.y b850307b279c 7ba05d2d .config log report