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INFO: task hung in con_install

Status: auto-closed as invalid on 2020/05/29 01:06
Reported-by: syzbot+ffce564ff2040d5bfacf@syzkaller.appspotmail.com
First crash: 1548d, last: 1548d
▶ ▼ 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 268d 268d 0/26 auto-obsoleted due to no activity on 2023/10/31 16:25
linux-4.14 INFO: task hung in con_install 1 1469d 1469d 0/1 auto-closed as invalid on 2020/08/16 15:03
linux-4.19 INFO: task hung in con_install (2) 1 1414d 1414d 0/1 auto-closed as invalid on 2020/10/09 22:35
upstream INFO: task hung in con_install serial 6 1389d 1571d 0/26 closed as dup on 2020/08/16 15:20

Sample crash report:
nla_parse: 18 callbacks suppressed
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.2'.
INFO: task syz-executor.3:16146 blocked for more than 140 seconds.
      Not tainted 4.19.100-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28200 16146  23289 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
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x176/0x2c0 kernel/locking/semaphore.c:238
 down+0x64/0x90 kernel/locking/semaphore.c:62
 console_lock+0x29/0x80 kernel/printk/printk.c:2244
 con_install+0x4a/0x410 drivers/tty/vt/vt.c:3203
 tty_driver_install_tty drivers/tty/tty_io.c:1226 [inline]
 tty_init_dev drivers/tty/tty_io.c:1339 [inline]
 tty_init_dev+0xf7/0x460 drivers/tty/tty_io.c:1316
 tty_open_by_driver drivers/tty/tty_io.c:1981 [inline]
 tty_open+0x4bf/0xb70 drivers/tty/tty_io.c:2029
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3421 [inline]
 path_openat+0x1108/0x4500 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_open fs/open.c:1106 [inline]
 __se_sys_open fs/open.c:1101 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1101
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4150e1
Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f4f64af87a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f4f64af96d4 RCX: 00000000004150e1
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f4f64af87d0
RBP: 000000000075bf20 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000bd4 R14: 00000000004ccb40 R15: 000000000075bf2c
INFO: task syz-executor.3:16150 blocked for more than 140 seconds.
      Not tainted 4.19.100-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28512 16150  23289 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
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x176/0x2c0 kernel/locking/semaphore.c:238
 down+0x64/0x90 kernel/locking/semaphore.c:62
 console_lock+0x29/0x80 kernel/printk/printk.c:2244
 vcs_open+0x67/0xd0 drivers/tty/vt/vc_screen.c:660
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3421 [inline]
 path_openat+0x1108/0x4500 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b349
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4f64ad7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f4f64ad86d4 RCX: 000000000045b349
RDX: 0000000000008000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007f7 R14: 00000000004c9631 R15: 000000000075bfd4
INFO: task syz-executor.5:16145 blocked for more than 140 seconds.
      Not tainted 4.19.100-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28240 16145   8036 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
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3421 [inline]
 path_openat+0x1108/0x4500 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b349
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fef93f11c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fef93f126d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000793 R14: 00000000004c8f72 R15: 000000000075bf2c

Showing all locks held in the system:
2 locks held by kworker/u4:3/989:
1 lock held by khungtaskd/1080:
 #0: 00000000be95145f (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
1 lock held by khugepaged/1087:
1 lock held by udevd/3773:
1 lock held by rsyslogd/7855:
 #0: 000000008b94a9f0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/7977:
 #0: 0000000014a7bea0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000e376c6a9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7978:
 #0: 000000004e4acf1c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 0000000076f810b2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7979:
 #0: 00000000cbdbc1ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000004bd9be2c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7980:
 #0: 00000000187d6c43 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000bfa2086e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7981:
 #0: 000000004f99d9cd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000dfbd6609 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7982:
 #0: 00000000b0233bc2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000ed927cda (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7983:
 #0: 000000006a4134e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000004ac0c218 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.3/16146:
 #0: 00000000d3947662 (tty_mutex){+.+.}, at: tty_open_by_driver drivers/tty/tty_io.c:1945 [inline]
 #0: 00000000d3947662 (tty_mutex){+.+.}, at: tty_open+0x3e5/0xb70 drivers/tty/tty_io.c:2029
 #1: 00000000b0de4559 (&tty->legacy_mutex){+.+.}, at: tty_lock+0x73/0xb0 drivers/tty/tty_mutex.c:19
1 lock held by syz-executor.5/16145:
 #0: 00000000f7b06c28 (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
3 locks held by syz-executor.5/16149:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1080 Comm: khungtaskd Not tainted 4.19.100-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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3773 Comm: udevd Not tainted 4.19.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_is_held+0x50/0x140 kernel/locking/lockdep.c:3720
Code: c4 48 89 c2 48 89 45 c8 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e cb 00 00 00 4c 8b 6d c8 <48> 8d 83 80 08 00 00 45 31 f6 48 89 45 d0 48 b8 00 00 00 00 00 fc
RSP: 0018:ffff888095b87a90 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888095b7a100 RCX: ffffffff81bf43bc
RDX: 1ffff11012b6f52f RSI: 00000000ffffffff RDI: ffff8880955fda60
RBP: ffff888095b87ad0 R08: ffff888095b7a100 R09: ffff888095b7a9a0
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880955fda60
R13: ffff888095b7a978 R14: ffff888095b87dc0 R15: ffff888095b87c60
FS:  00007f975ac8f7a0(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c42269dda0 CR3: 00000000959ec000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_is_held_type+0x110/0x210 kernel/locking/lockdep.c:3941
 lock_is_held include/linux/lockdep.h:344 [inline]
 ep_wakeup_source fs/eventpoll.c:630 [inline]
 ep_send_events_proc+0x3e9/0xc10 fs/eventpoll.c:1654
 ep_scan_ready_list+0x305/0xb20 fs/eventpoll.c:708
 ep_send_events fs/eventpoll.c:1713 [inline]
 ep_poll+0x3b4/0xd10 fs/eventpoll.c:1840
 do_epoll_wait+0x1b3/0x200 fs/eventpoll.c:2198
 __do_sys_epoll_wait fs/eventpoll.c:2208 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2205 [inline]
 __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2205
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f975a3a3943
Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24
RSP: 002b:00007fff6962f7e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f975a3a3943
RDX: 0000000000000008 RSI: 00007fff6962f8e0 RDI: 000000000000000a
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000700ea0 R15: 00000000006ca030

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/30 01:06 linux-4.19.y 7cdefde351b6 5ed23f9a .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.