syzbot


INFO: task hung in tty_open

Status: auto-closed as invalid on 2022/01/02 10:09
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 312d, last: 312d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in tty_open C 132 1002d 1218d 0/2 public: reported C repro on 2019/04/13 00:00
upstream INFO: task hung in tty_open (2) C error error 16 3d14h 187d 0/23 upstream: reported C repro on 2022/02/07 03:39
linux-4.14 INFO: task hung in tty_open 2 754d 805d 0/1 auto-closed as invalid on 2020/11/17 06:29
android-414 INFO: task hung in tty_open C 152 1198d 1220d 0/1 public: reported C repro on 2019/04/11 00:00
android-49 INFO: task hung in tty_open C 447 983d 1219d 0/3 public: reported C repro on 2019/04/12 00:00
upstream INFO: task can't die in irqentry_exit (2) C error 22 192d 608d 0/23 upstream: reported C repro on 2020/12/13 03:25
upstream INFO: task can't die in show_free_areas C error 11 190d 200d 0/23 upstream: reported C repro on 2022/01/24 13:23

Sample crash report:
INFO: task syz-executor.3:14107 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:28376 pid:14107 ppid: 12219 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 tty_open_by_driver drivers/tty/tty_io.c:2062 [inline]
 tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2146
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4c8/0x11d0 fs/open.c:822
 do_open fs/namei.c:3428 [inline]
 path_openat+0x1c9a/0x2740 fs/namei.c:3561
 do_filp_open+0x1aa/0x400 fs/namei.c:3588
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_openat fs/open.c:1232 [inline]
 __se_sys_openat fs/open.c:1227 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc4643ec7f4
RSP: 002b:00007fc46196dcc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc46453e0e0 RCX: 00007fc4643ec7f4
RDX: 0000000000000002 RSI: 00007fc46196dd60 RDI: 00000000ffffff9c
RBP: 00007fc46196dd60 R08: 0000000000000000 R09: 000000000000000d
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
R13: 00007ffd6726cb8f R14: 00007fc46196e300 R15: 0000000000022000
INFO: task syz-executor.5:14067 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:26944 pid:14067 ppid: 10738 flags:0x00000004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425
 __mutex_lock_common kernel/locking/mutex.c:669 [inline]
 __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729
 tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1716
 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1878
 __fput+0x288/0x9f0 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f27e3c5d51b
RSP: 002b:00007fffea705590 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f27e3c5d51b
RDX: 0000001b31434840 RSI: ffffffff89368c58 RDI: 0000000000000004
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b3143388c
R10: 000000000000070f R11: 0000000000000293 R12: 00007f27e3dafb60
R13: 00007f27e3dafb60 R14: 00007f27e3daef60 R15: 00000000001149e0
INFO: task syz-executor.5:14076 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:27280 pid:14076 ppid: 10738 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
 __down_common+0x2e0/0x420 kernel/locking/semaphore.c:224
 down+0x72/0xa0 kernel/locking/semaphore.c:62
 console_lock+0x2a/0x80 kernel/printk/printk.c:2523
 con_install+0x8e/0x620 drivers/tty/vt/vt.c:3381
 tty_driver_install_tty drivers/tty/tty_io.c:1315 [inline]
 tty_init_dev.part.0+0x9e/0x610 drivers/tty/tty_io.c:1429
 tty_init_dev include/linux/err.h:36 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:2098 [inline]
 tty_open+0xb16/0x1000 drivers/tty/tty_io.c:2146
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4c8/0x11d0 fs/open.c:822
 do_open fs/namei.c:3428 [inline]
 path_openat+0x1c9a/0x2740 fs/namei.c:3561
 do_filp_open+0x1aa/0x400 fs/namei.c:3588
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_openat fs/open.c:1232 [inline]
 __se_sys_openat fs/open.c:1227 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1227
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f27e3c5d7f4
RSP: 002b:00007f27e1220cc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f27e3daef60 RCX: 00007f27e3c5d7f4
RDX: 0000000000000002 RSI: 00007f27e1220d60 RDI: 00000000ffffff9c
RBP: 00007f27e1220d60 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002
R13: 00007fffea70552f R14: 00007f27e1221300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8b97fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
1 lock held by in:imklog/6226:
 #0: ffff88801e3aa370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
5 locks held by syz-executor.3/14070:
1 lock held by syz-executor.3/14107:
 #0: ffffffff8c3888a8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2062 [inline]
 #0: ffffffff8c3888a8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2146
1 lock held by syz-executor.5/14067:
 #0: ffffffff8c3888a8 (tty_mutex){+.+.}-{3:3}, at: tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1716
2 locks held by syz-executor.5/14076:
 #0: ffffffff8c3888a8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2062 [inline]
 #0: ffffffff8c3888a8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2146
 #1: ffff88802b6921c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock+0xbd/0x120 drivers/tty/tty_mutex.c:20

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 14070 Comm: syz-executor.3 Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:slow_down_io arch/x86/include/asm/paravirt.h:55 [inline]
RIP: 0010:inb_p arch/x86/include/asm/io.h:334 [inline]
RIP: 0010:vga_io_r include/video/vga.h:204 [inline]
RIP: 0010:vga_io_rgfx include/video/vga.h:389 [inline]
RIP: 0010:setop drivers/video/fbdev/vga16fb.c:149 [inline]
RIP: 0010:vga_8planes_imageblit drivers/video/fbdev/vga16fb.c:1138 [inline]
RIP: 0010:vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1203 [inline]
RIP: 0010:vga16fb_imageblit+0x16bd/0x2200 drivers/video/fbdev/vga16fb.c:1260
Code: c7 c2 60 5f 7f 8b 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 0e 07 00 00 ff 15 99 e8 6e 07 ba cf 03 00 00 ec <48> c7 c2 60 5f 7f 8b 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80
RSP: 0018:ffffc900030eef70 EFLAGS: 00000246
RAX: dffffc00000000ff RBX: 0000000000000ce8 RCX: 0000000000000000
RDX: 00000000000003cf RSI: ffffffff841071bc RDI: ffffc900030ef108
RBP: ffff8880000a0ce8 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff84106705 R11: 0000000000000001 R12: ffffc900030ef10c
R13: ffff888145830216 R14: ffff8880000a0000 R15: ffffc900030ef0f8
FS:  00007fc4619b0700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c014b37d20 CR3: 0000000019a0b000 CR4: 0000000000350ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
 bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188
 fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1296
 fbcon_redraw.constprop.0+0x41a/0x4b0 drivers/video/fbdev/core/fbcon.c:1672
 fbcon_scroll+0x1d7a/0x3580 drivers/video/fbdev/core/fbcon.c:1782
 con_scroll+0x5b9/0x6d0 drivers/tty/vt/vt.c:630
 lf+0x26b/0x2c0 drivers/tty/vt/vt.c:1507
 vc_con_write_normal drivers/tty/vt/vt.c:2851 [inline]
 do_con_write+0xf1c/0x1e40 drivers/tty/vt/vt.c:2955
 con_write+0x21/0x40 drivers/tty/vt/vt.c:3295
 n_tty_write+0xa7a/0xfd0 drivers/tty/n_tty.c:2311
 do_tty_write drivers/tty/tty_io.c:1038 [inline]
 file_tty_write.constprop.0+0x526/0x910 drivers/tty/tty_io.c:1110
 call_write_iter include/linux/fs.h:2163 [inline]
 do_iter_readv_writev+0x472/0x750 fs/read_write.c:729
 do_iter_write+0x188/0x710 fs/read_write.c:855
 vfs_iter_write+0x70/0xa0 fs/read_write.c:896
 iter_file_splice_write+0x723/0xc70 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x110/0x180 fs/splice.c:936
 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891
 do_splice_direct+0x1b3/0x280 fs/splice.c:979
 do_sendfile+0xae9/0x1240 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1314 [inline]
 __se_sys_sendfile64 fs/read_write.c:1300 [inline]
 __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1300
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc4644398d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc4619b0188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fc46453df60 RCX: 00007fc4644398d9
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007fc464493cb4 R08: 0000000000000000 R09: 0000000000000000
R10: 0800000080004103 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6726cb8f R14: 00007fc4619b0300 R15: 0000000000022000
----------------
Code disassembly (best guess):
   0:	c7 c2 60 5f 7f 8b    	mov    $0x8b7f5f60,%edx
   6:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   d:	fc ff df
  10:	48 c1 ea 03          	shr    $0x3,%rdx
  14:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  18:	0f 85 0e 07 00 00    	jne    0x72c
  1e:	ff 15 99 e8 6e 07    	callq  *0x76ee899(%rip)        # 0x76ee8bd
  24:	ba cf 03 00 00       	mov    $0x3cf,%edx
  29:	ec                   	in     (%dx),%al
* 2a:	48 c7 c2 60 5f 7f 8b 	mov    $0xffffffff8b7f5f60,%rdx <-- trapping instruction
  31:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  38:	fc ff df
  3b:	48 c1 ea 03          	shr    $0x3,%rdx
  3f:	80                   	.byte 0x80

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2021/10/04 10:05 upstream 9e1ff307c779 ce697b49 .config log report info INFO: task hung in tty_open