syzbot


INFO: task hung in ubi_detach_mtd_dev

Status: auto-closed as invalid on 2020/06/24 16:43
Reported-by: syzbot+5995967f7e142b6caccf@syzkaller.appspotmail.com
First crash: 902d, last: 902d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in ubi_detach_mtd_dev (2) syz error 1 761d 761d 0/1 upstream: reported syz repro on 2020/07/15 16:30
upstream INFO: task hung in ubi_detach_mtd_dev syz error error 4 817d 904d 17/23 fixed on 2020/11/16 12:12
linux-4.14 INFO: task hung in ubi_detach_mtd_dev 6 773d 864d 0/1 auto-closed as invalid on 2020/11/01 05:07

Sample crash report:
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task syz-executor.4:19129 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D26032 19129   8099 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782
 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+0x116/0x6c0 kernel/kthread.c:550
 ubi_detach_mtd_dev+0x219/0x402 drivers/mtd/ubi/build.c:1093
 ctrl_cdev_ioctl+0x1d6/0x2d0 drivers/mtd/ubi/cdev.c:1051
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007f93487aec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f93487af6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.4:19133 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D27608 19133   8099 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007f934878dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f934878e6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 000000000000000a
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.1:19132 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D25824 19132   8086 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007f85639cfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f85639d06d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.1:19134 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D27672 19134   8086 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007f85639aec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f85639af6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 000000000000000a
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.5:19137 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D27880 19137   8102 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007fb401d24c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb401d256d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.0:19204 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D26304 19204   8083 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007fcac10d6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcac10d76d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.0:19242 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D27608 19242   8083 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007fcac10b5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcac10b66d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 000000000000000a
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.2:19245 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D26704 19245   8095 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007f296ed43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f296ed446d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c
INFO: task syz-executor.2:19247 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D27608 19247   8095 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007f296ed22c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f296ed236d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040186f40 RDI: 000000000000000a
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bfcc
INFO: task syz-executor.3:19250 blocked for more than 140 seconds.
      Not tainted 4.19.106-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D27880 19250   8097 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: 1a 48 39 d9 75 23 0f b6 48 08 0f b6 5a 08 38 d9 75 13 48 8b 40 10 48 8b 4a 10 48 39 c8 0f 94 c0 88 44 24 18 c3 31 c0 eb f7 31 <c0> eb f3 cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68
RSP: 002b:00007fa81d73ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa81d73f6d4 RCX: 000000000045c449
RDX: 000000000076006e RSI: 0000000040046f41 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000207 R14: 00000000004c3e89 R15: 000000000076bf2c

Showing all locks held in the system:
2 locks held by kworker/u4:3/324:
1 lock held by khungtaskd/1080:
 #0: 0000000096720062 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
1 lock held by rsyslogd/7917:
 #0: 000000005264109a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/8040:
 #0: 000000007035c205 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000007cbe4413 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8041:
 #0: 00000000990624ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000fa1f0532 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8042:
 #0: 00000000472b6ded (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000010ad8f88 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8043:
 #0: 00000000fa03b25f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000acd28000 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8044:
 #0: 000000007d7c9fe1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000033bc3af7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8045:
 #0: 000000002b97050d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000befb7248 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8046:
 #0: 000000006aa5a9dc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000001b07a041 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
1 lock held by syz-executor.4/19129:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
1 lock held by syz-executor.4/19133:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
1 lock held by syz-executor.1/19132:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
1 lock held by syz-executor.1/19134:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
1 lock held by syz-executor.5/19137:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
1 lock held by syz-executor.0/19204:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
1 lock held by syz-executor.0/19242:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
1 lock held by syz-executor.2/19245:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
1 lock held by syz-executor.2/19247:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025
1 lock held by syz-executor.3/19250:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x1cd/0x2d0 drivers/mtd/ubi/cdev.c:1050
1 lock held by syz-executor.3/19251:
 #0: 00000000ffb2cdb6 (ubi_devices_mutex){+.+.}, at: ctrl_cdev_ioctl+0x22b/0x2d0 drivers/mtd/ubi/cdev.c:1025

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

NMI backtrace for cpu 1
CPU: 1 PID: 1080 Comm: khungtaskd Not tainted 4.19.106-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+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2020/02/25 16:42 linux-4.19.y f25804f38984 4c886d6a .config log report