syzbot


INFO: task hung in con_install (2)

Status: auto-closed as invalid on 2020/10/09 22:35
Reported-by: syzbot+487b058f2be7457c1105@syzkaller.appspotmail.com
First crash: 1625d, last: 1625d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in con_install (2) serial 1 478d 478d 0/28 auto-obsoleted due to no activity on 2023/10/31 16:25
linux-4.14 INFO: task hung in con_install 1 1679d 1679d 0/1 auto-closed as invalid on 2020/08/16 15:03
upstream INFO: task hung in con_install serial 6 1599d 1782d 0/28 closed as dup on 2020/08/16 15:20
linux-4.19 INFO: task hung in con_install 1 1759d 1759d 0/1 auto-closed as invalid on 2020/05/29 01:06

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.5:13851 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28592 13851   6914 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x8f3/0xed0 kernel/time/timer.c:1782
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x192/0x2b0 kernel/locking/semaphore.c:238
 down+0x57/0x80 kernel/locking/semaphore.c:62
 console_lock+0x25/0x80 kernel/printk/printk.c:2244
 con_install+0x8b/0x5f0 drivers/tty/vt/vt.c:3231
 tty_driver_install_tty drivers/tty/tty_io.c:1226 [inline]
 tty_init_dev drivers/tty/tty_io.c:1339 [inline]
 tty_init_dev+0xee/0x450 drivers/tty/tty_io.c:1316
 tty_open_by_driver drivers/tty/tty_io.c:1981 [inline]
 tty_open+0x6a4/0x950 drivers/tty/tty_io.c:2029
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416861
Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 <e8> 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9
RSP: 002b:00007f80a27237a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000509d80 RCX: 0000000000416861
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f80a27237d0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c32 R14: 00000000004ce8ab R15: 00007f80a27246d4
INFO: task syz-executor.5:13862 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D29296 13862   6914 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416861
Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 <e8> 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9
RSP: 002b:00007f80a27027a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000509d80 RCX: 0000000000416861
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f80a27027d0
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c32 R14: 00000000004ce8ab R15: 00007f80a27036d4
INFO: task syz-executor.5:13864 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D26928 13864   6914 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416861
Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 <e8> 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9
RSP: 002b:00007f80a26e17a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000509d80 RCX: 0000000000416861
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f80a26e17d0
RBP: 000000000078c040 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c32 R14: 00000000004ce8ab R15: 00007f80a26e26d4
INFO: task syz-executor.5:13885 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D29296 13885   6914 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416861
Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 <e8> 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9
RSP: 002b:00007f80a26c07a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000509d80 RCX: 0000000000416861
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f80a26c07d0
RBP: 000000000078c0e0 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c32 R14: 00000000004ce8ab R15: 00007f80a26c16d4
INFO: task syz-executor.4:13883 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D29456 13883   6827 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca69
Code: 48 c7 44 24 10 00 00 00 00 48 8b 44 24 68 48 89 44 24 18 48 8b 44 24 70 48 89 44 24 20 48 8b 44 24 78 48 89 44 24 28 48 89 4c <24> 30 0f 57 c0 0f 11 44 24 38 48 c7 44 24 48 00 00 00 00 e8 0f d4
RSP: 002b:00007f84c6cd9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f7ec0 RCX: 000000000045ca69
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007b7 R14: 00000000004ca96d R15: 00007f84c6cda6d4
INFO: task syz-executor.0:13855 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29456 13855   8425 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca69
Code: 48 c7 44 24 10 00 00 00 00 48 8b 44 24 68 48 89 44 24 18 48 8b 44 24 70 48 89 44 24 20 48 8b 44 24 78 48 89 44 24 28 48 89 4c <24> 30 0f 57 c0 0f 11 44 24 38 48 c7 44 24 48 00 00 00 00 e8 0f d4
RSP: 002b:00007f3a761f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f7ec0 RCX: 000000000045ca69
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007b7 R14: 00000000004ca96d R15: 00007f3a761fa6d4
INFO: task syz-executor.0:13860 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29456 13860   8425 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca69
Code: 48 c7 44 24 10 00 00 00 00 48 8b 44 24 68 48 89 44 24 18 48 8b 44 24 70 48 89 44 24 20 48 8b 44 24 78 48 89 44 24 28 48 89 4c <24> 30 0f 57 c0 0f 11 44 24 38 48 c7 44 24 48 00 00 00 00 e8 0f d4
RSP: 002b:00007f3a761d8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f7ec0 RCX: 000000000045ca69
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007b7 R14: 00000000004ca96d R15: 00007f3a761d96d4
INFO: task syz-executor.1:13858 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D29104 13858   6558 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416861
Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 <e8> 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9
RSP: 002b:00007fcd1f93e7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000509d80 RCX: 0000000000416861
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007fcd1f93e7d0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c32 R14: 00000000004ce8ab R15: 00007fcd1f93f6d4
INFO: task syz-executor.1:13863 blocked for more than 140 seconds.
      Not tainted 4.19.128-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D29296 13863   6558 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x5b8/0x1300 kernel/locking/mutex.c:1072
 tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
 chrdev_open+0x219/0x5c0 fs/char_dev.c:423
 do_dentry_open+0x4a8/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0xe06/0x2eb0 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3aa/0x510 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416861
Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 <e8> 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9
RSP: 002b:00007fcd1f91d7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000509d80 RCX: 0000000000416861
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007fcd1f91d7d0
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c32 R14: 00000000004ce8ab R15: 00007fcd1f91e6d4

Showing all locks held in the system:
1 lock held by khungtaskd/1072:
 #0: 00000000279141d5 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by in:imklog/6104:
 #0: 000000004731a565 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767
1 lock held by syz-executor.4/8920:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1623
2 locks held by syz-executor.5/13851:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
 #1: 000000004002b83a (&tty->legacy_mutex){+.+.}, at: tty_lock+0x6a/0xa0 drivers/tty/tty_mutex.c:19
1 lock held by syz-executor.5/13862:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
1 lock held by syz-executor.5/13864:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
1 lock held by syz-executor.5/13885:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
3 locks held by syz-executor.4/13852:
1 lock held by syz-executor.4/13883:
 #0: 00000000fef84631 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.0/13855:
 #0: 00000000fef84631 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.0/13860:
 #0: 00000000fef84631 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.1/13858:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open+0x391/0x950 drivers/tty/tty_io.c:2029
1 lock held by syz-executor.1/13863:
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000930dc7e4 (tty_mutex){+.+.}, at: tty_open+0x391/0x950 drivers/tty/tty_io.c:2029

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

NMI backtrace for cpu 0
CPU: 0 PID: 1072 Comm: khungtaskd Not tainted 4.19.128-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+0x1fc/0x2fe lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x962/0xe40 kernel/hung_task.c:287
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13852 Comm: syz-executor.4 Not tainted 4.19.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:62 [inline]
RIP: 0010:bitfill_aligned+0xdf/0x200 drivers/video/fbdev/core/cfbfillrect.c:35
Code: fd e8 a5 7d f0 fd 31 ff 44 89 fe e8 0b 7f f0 fd 45 85 ff 0f 85 f9 00 00 00 e8 8d 7d f0 fd 44 89 e0 31 d2 bf 07 00 00 00 f7 f5 <41> 89 c4 89 c6 89 c5 e8 e5 7e f0 fd 41 83 fc 07 76 62 45 89 e7 4c
RSP: 0018:ffff88805488f200 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffc9000e2e8000
RDX: 0000000000000000 RSI: ffffffff83771d33 RDI: 0000000000000007
RBP: 0000000000000040 R08: ffff888087f08580 R09: 0000000000000040
R10: ffffed1014ab2f3b R11: ffff8880a55979df R12: 0000000000000080
R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f84c6cfb700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00eacaa30 CR3: 00000000941f9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 cfb_fillrect+0x418/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327
 vga16fb_fillrect+0x68f/0x1960 drivers/video/fbdev/vga16fb.c:951
 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x2c7/0x350 drivers/video/fbdev/core/fbcon.c:1342
 fbcon_switch+0xd9f/0x18f0 drivers/video/fbdev/core/fbcon.c:2324
 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1015
 fbcon_modechanged+0x5a0/0x870 drivers/video/fbdev/core/fbcon.c:2972
 fbcon_event_notify+0x1b2/0x1d60 drivers/video/fbdev/core/fbcon.c:3347
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325
 fb_set_var+0xc39/0xe00 drivers/video/fbdev/core/fbmem.c:1042
 do_fb_ioctl+0x450/0x9c0 drivers/video/fbdev/core/fbmem.c:1115
 fb_ioctl+0xda/0x120 drivers/video/fbdev/core/fbmem.c:1230
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca69
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f84c6cfac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e4ec0 RCX: 000000000045ca69
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002f7 R14: 00000000004c5771 R15: 00007f84c6cfb6d4

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/11 22:34 linux-4.19.y 3fc898571b97 1beaee21 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.