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INFO: task hung in release_tty

Status: auto-closed as invalid on 2020/06/30 16:07
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+585ef057d3538fcc1639@syzkaller.appspotmail.com
First crash: 1576d, last: 1514d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
INFO: task hung in release_tty 0 (1) 2020/01/07 08:17
▶ ▼ Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in release_tty (2) serial 2 899d 976d 0/26 auto-closed as invalid on 2022/02/05 17:28
linux-4.19 INFO: task hung in release_tty 2 1373d 1446d 0/1 auto-closed as invalid on 2020/11/18 01:32
linux-4.14 INFO: task hung in release_tty 6 1379d 1578d 0/1 auto-closed as invalid on 2020/11/12 17:59

Sample crash report:
INFO: task syz-executor.2:11118 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.2  D28264 11118   8783 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x87f/0xcd0 kernel/sched/core.c:4080
 schedule+0x188/0x210 kernel/sched/core.c:4154
 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871
 __down_common+0x28c/0x510 kernel/locking/semaphore.c:220
 __down+0x18/0x20 kernel/locking/semaphore.c:237
 down+0x6b/0xb0 kernel/locking/semaphore.c:61
 console_lock+0x28/0x70 kernel/printk/printk.c:2289
 con_shutdown+0x48/0x80 drivers/tty/vt/vt.c:3288
 release_tty+0xc1/0x530 drivers/tty/tty_io.c:1514
 tty_release_struct+0xc3/0xe0 drivers/tty/tty_io.c:1629
 tty_release+0xceb/0xfb0 drivers/tty/tty_io.c:1789
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x176/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:164 [inline]
 prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416011
Code: 49 89 fc 48 83 e7 0f 48 81 cf f0 00 00 00 49 8d 43 04 4c 39 d0 0f 83 ec 00 00 00 41 88 38 90 49 c1 ec 04 48 39 d6 74 5d 49 83 <f9> 08 73 48 0f b6 02 48 89 cf 4c 89 c9 48 d3 e0 49 09 c4 90 48 8d
RSP: 002b:00007fff29731df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 000000000000000e RCX: 0000000000416011
RDX: 0000000000000000 RSI: 000000000000033c RDI: 000000000000000d
RBP: 0000000000000001 R08: 0000000076c10340 R09: 00ffffffffffffff
R10: 00007fff29731ed0 R11: 0000000000000293 R12: 000000000076c920
R13: 000000000076c920 R14: 0000000000041e13 R15: 000000000076c24c
INFO: task syz-executor.4:11166 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.4  D28248 11166   8791 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x87f/0xcd0 kernel/sched/core.c:4080
 schedule+0x188/0x210 kernel/sched/core.c:4154
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213
 __mutex_lock_common+0x11f1/0x2f30 kernel/locking/mutex.c:1033
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118
 lock_fb_info include/linux/fb.h:637 [inline]
 fb_open+0x15e/0x3e0 drivers/video/fbdev/core/fbmem.c:1418
 chrdev_open+0x509/0x590 fs/char_dev.c:414
 do_dentry_open+0x85b/0x10c0 fs/open.c:797
 vfs_open+0x73/0x80 fs/open.c:914
 do_last fs/namei.c:3490 [inline]
 path_openat+0x16f1/0x4380 fs/namei.c:3607
 do_filp_open+0x192/0x3d0 fs/namei.c:3637
 do_sys_openat2+0x42b/0x6f0 fs/open.c:1149
 do_sys_open fs/open.c:1165 [inline]
 __do_sys_openat fs/open.c:1179 [inline]
 __se_sys_openat fs/open.c:1174 [inline]
 __x64_sys_openat+0x1e6/0x210 fs/open.c:1174
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c479
Code: 15 08 c5 01 48 89 04 24 48 8d 44 24 28 48 89 44 24 08 e8 ea 87 fa ff 48 8d 7c 24 78 0f 57 c0 48 8d 7f d0 48 89 6c 24 f0 48 8d <6c> 24 f0 e8 d4 33 00 00 48 8b 6d 00 48 c7 44 24 38 00 00 00 00 66
RSP: 002b:00007f97b4e5dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f97b4e5e6d4 RCX: 000000000045c479
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000799 R14: 00000000004ca0ce R15: 000000000076bf2c
INFO: task syz-executor.0:11180 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.0  D27816 11180   8774 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x87f/0xcd0 kernel/sched/core.c:4080
 schedule+0x188/0x210 kernel/sched/core.c:4154
 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871
 __down_common+0x28c/0x510 kernel/locking/semaphore.c:220
 __down+0x18/0x20 kernel/locking/semaphore.c:237
 down+0x6b/0xb0 kernel/locking/semaphore.c:61
 console_lock+0x28/0x70 kernel/printk/printk.c:2289
 vcs_open+0x67/0xe0 drivers/tty/vt/vc_screen.c:688
 chrdev_open+0x509/0x590 fs/char_dev.c:414
 do_dentry_open+0x85b/0x10c0 fs/open.c:797
 vfs_open+0x73/0x80 fs/open.c:914
 do_last fs/namei.c:3490 [inline]
 path_openat+0x16f1/0x4380 fs/namei.c:3607
 do_filp_open+0x192/0x3d0 fs/namei.c:3637
 do_sys_openat2+0x42b/0x6f0 fs/open.c:1149
 do_sys_open fs/open.c:1165 [inline]
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_open fs/open.c:1171 [inline]
 __se_sys_open fs/open.c:1169 [inline]
 __x64_sys_open+0x1bd/0x1e0 fs/open.c:1169
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416211
Code: 4c 89 f6 49 89 d6 e9 c2 f9 ff ff 48 89 c8 48 89 d3 4d 89 d6 4c 89 f2 31 c9 45 31 ed 45 31 ff 49 89 f2 31 f6 e9 a4 f9 ff ff 49 <8b> 49 08 49 8b 19 4c 89 04 24 89 7c 24 08 89 44 24 0c 48 89 74 24
RSP: 002b:00007f0ab0d217a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416211
RDX: 0000000000000000 RSI: 0000000000000101 RDI: 00007f0ab0d21850
RBP: 000000000076bf20 R08: 000000000000000f R09: 0000000000000000
R10: 000000000000fec8 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c14 R14: 00000000004ce00d R15: 000000000076bf2c
INFO: task syz-executor.0:11185 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.0  D28360 11185   8774 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x87f/0xcd0 kernel/sched/core.c:4080
 schedule+0x188/0x210 kernel/sched/core.c:4154
 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871
 __down_common+0x28c/0x510 kernel/locking/semaphore.c:220
 __down+0x18/0x20 kernel/locking/semaphore.c:237
 down+0x6b/0xb0 kernel/locking/semaphore.c:61
 console_lock+0x28/0x70 kernel/printk/printk.c:2289
 vcs_open+0x67/0xe0 drivers/tty/vt/vc_screen.c:688
 chrdev_open+0x509/0x590 fs/char_dev.c:414
 do_dentry_open+0x85b/0x10c0 fs/open.c:797
 vfs_open+0x73/0x80 fs/open.c:914
 do_last fs/namei.c:3490 [inline]
 path_openat+0x16f1/0x4380 fs/namei.c:3607
 do_filp_open+0x192/0x3d0 fs/namei.c:3637
 do_sys_openat2+0x42b/0x6f0 fs/open.c:1149
 do_sys_open fs/open.c:1165 [inline]
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_open fs/open.c:1171 [inline]
 __se_sys_open fs/open.c:1169 [inline]
 __x64_sys_open+0x1bd/0x1e0 fs/open.c:1169
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x416211
Code: 4c 89 f6 49 89 d6 e9 c2 f9 ff ff 48 89 c8 48 89 d3 4d 89 d6 4c 89 f2 31 c9 45 31 ed 45 31 ff 49 89 f2 31 f6 e9 a4 f9 ff ff 49 <8b> 49 08 49 8b 19 4c 89 04 24 89 7c 24 08 89 44 24 0c 48 89 74 24
RSP: 002b:00007f0ab0cdf7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416211
RDX: 0000000000000000 RSI: 0000000000000101 RDI: 00007f0ab0cdf850
RBP: 000000000076c060 R08: 000000000000000f R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c14 R14: 00000000004ce00d R15: 000000000076c06c

Showing all locks held in the system:
1 lock held by khungtaskd/1120:
 #0: ffffffff892d9948 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207
1 lock held by rsyslogd/8642:
 #0: ffff8880a9521860 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x279/0x310 fs/file.c:821
2 locks held by getty/8732:
 #0: ffff88808d797090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc9000174b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
2 locks held by getty/8733:
 #0: ffff888094c9d090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc900017ab2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
2 locks held by getty/8734:
 #0: ffff8880970bb090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc9000177b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
2 locks held by getty/8735:
 #0: ffff8880977c1090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc9000173b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
2 locks held by getty/8736:
 #0: ffff88808c8bd090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc9000179b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
2 locks held by getty/8737:
 #0: ffff8880a0c76090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc900017032e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
2 locks held by getty/8738:
 #0: ffff88809a837090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267
 #1: ffffc900016fb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.2/11118:
 #0: ffffffff89461550 (tty_mutex){+.+.}, at: tty_release_struct+0xb8/0xe0 drivers/tty/tty_io.c:1628
2 locks held by syz-executor.5/11159:
1 lock held by syz-executor.4/11166:
 #0: ffff8880a38f8070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline]
 #0: ffff8880a38f8070 (&fb_info->lock){+.+.}, at: fb_open+0x15e/0x3e0 drivers/video/fbdev/core/fbmem.c:1418

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

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+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaa/0x190 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x16f/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xd40/0xd60 kernel/hung_task.c:289
 kthread+0x332/0x350 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
CPU: 1 PID: 11159 Comm: syz-executor.5 Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:180
Code: 0f 0b e8 23 00 00 00 0f 0b 90 55 48 89 e5 53 48 89 fb e8 13 00 00 00 48 8b 3d f4 a1 f2 07 48 89 de e8 84 b4 3c 00 5b 5d c3 cc <55> 48 89 e5 48 8b 45 08 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 34 04
RSP: 0018:ffffc90002e4f798 EFLAGS: 00000286
RAX: ffffffff83d0b788 RBX: 0000000000000038 RCX: 0000000000040000
RDX: ffffc90015885000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc90002e4f7f0 R08: ffffffff83d0b73d R09: 0000000000000040
R10: ffff88808b7f8440 R11: 0000000000000002 R12: ffff8880000a00b8
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffffffffff
FS:  00007f2f37f18700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f974fa20275 CR3: 00000000a4471000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 cfb_fillrect+0x57b/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327
 vga16fb_fillrect+0x642/0x1470 drivers/video/fbdev/vga16fb.c:951
 bit_clear_margins+0x368/0x620 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1379 [inline]
 fbcon_switch+0x1504/0x1f10 drivers/video/fbdev/core/fbcon.c:2361
 redraw_screen+0x56e/0x1830 drivers/tty/vt/vt.c:1008
 fbcon_modechanged+0x810/0xdf0 drivers/video/fbdev/core/fbcon.c:2998
 fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3045
 fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c479
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:00007f2f37f17c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2f37f186d4 RCX: 000000000045c479
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002ef R14: 00000000004c5096 R15: 000000000076bf2c

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/03/02 16:06 upstream 63623fd44972 c88c7b75 .config console log report ci-upstream-kasan-gce-smack-root
2020/01/10 12:56 upstream e69ec487b2c7 4de4e9f0 .config console log report ci-upstream-kasan-gce-root
2019/12/31 04:00 upstream fd6988496e79 7f117e28 .config console log report ci-upstream-kasan-gce
* Struck through repros no longer work on HEAD.