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INFO: task hung in vcs_open (2)

Status: auto-closed as invalid on 2020/12/23 12:34
Subsystems: serial
[Documentation on labels]
First crash: 1905d, last: 1905d
▶ ▼ Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in vcs_open (5) serial 1 2 1012d 1016d 0/29 auto-obsoleted due to no activity on 2023/06/04 04:45
upstream INFO: task hung in vcs_open (9) kernel 1 11 213d 379d 0/29 auto-obsoleted due to no activity on 2025/08/10 23:55
upstream INFO: task hung in vcs_open (3) serial 1 1 1755d 1755d 0/29 auto-closed as invalid on 2021/05/22 19:06
upstream INFO: task hung in vcs_open serial 1 32 1925d 2058d 0/29 closed as dup on 2020/08/05 10:53
upstream INFO: task hung in vcs_open (7) serial 1 1 635d 635d 0/29 auto-obsoleted due to no activity on 2024/06/15 13:53
linux-4.19 INFO: task hung in vcs_open 1 11 1861d 2174d 0/1 auto-closed as invalid on 2021/03/07 01:31
upstream INFO: task hung in vcs_open (4) serial 1 2 1166d 1228d 0/29 auto-obsoleted due to no activity on 2023/01/02 16:56
linux-4.14 INFO: task hung in vcs_open 1 3 2019d 2102d 0/1 auto-closed as invalid on 2020/09/30 10:12
upstream INFO: task hung in vcs_open (6) serial 1 2 785d 849d 0/29 auto-obsoleted due to no activity on 2024/01/17 08:03
linux-4.19 INFO: task hung in vcs_open (2) 1 1 1144d 1144d 0/1 auto-obsoleted due to no activity on 2023/02/22 05:12
upstream INFO: task hung in vcs_open (8) nilfs serial 1 C inconclusive 7 436d 442d 28/29 fixed on 2024/11/12 23:31

Sample crash report:
INFO: task syz-executor.3:4666 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:28360 pid: 4666 ppid:  6882 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0xec9/0x2280 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 __down_common kernel/locking/semaphore.c:220 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:237
 down+0x57/0x80 kernel/locking/semaphore.c:61
 console_lock+0x25/0x80 kernel/printk/printk.c:2317
 vcs_open+0x62/0xc0 drivers/tty/vt/vc_screen.c:688
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x11b0 fs/open.c:817
 do_open fs/namei.c:3251 [inline]
 path_openat+0x1b9a/0x2730 fs/namei.c:3368
 do_filp_open+0x17e/0x3c0 fs/namei.c:3395
 do_sys_openat2+0x16d/0x420 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1195
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: Bad RIP value.
RSP: 002b:00007f5f145cbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000242c0 RCX: 000000000045e179
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000118cf88 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffed140334f R14: 00007f5f145cc9c0 R15: 000000000118cf4c
INFO: task syz-executor.1:4695 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:28360 pid: 4695 ppid:  6878 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0xec9/0x2280 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
 lock_fb_info include/linux/fb.h:636 [inline]
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1414
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x4b9/0x11b0 fs/open.c:817
 do_open fs/namei.c:3251 [inline]
 path_openat+0x1b9a/0x2730 fs/namei.c:3368
 do_filp_open+0x17e/0x3c0 fs/namei.c:3395
 do_sys_openat2+0x16d/0x420 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1195
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: Bad RIP value.
RSP: 002b:00007f1ca6f5ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000227c0 RCX: 000000000045e179
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000118d030 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cff4
R13: 00007ffc87a1bbff R14: 00007f1ca6f5b9c0 R15: 000000000118cff4

Showing all locks held in the system:
1 lock held by khungtaskd/1174:
 #0: ffffffff8a067f00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5852
1 lock held by in:imklog/6767:
 #0: ffff88809a58c5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
2 locks held by syz-executor.1/4675:
1 lock held by syz-executor.1/4695:
 #0: ffff888218513078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:636 [inline]
 #0: ffff888218513078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1414

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

NMI backtrace for cpu 1
CPU: 1 PID: 1174 Comm: khungtaskd Not tainted 5.9.0-rc6-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+0x198/0x1fd lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4675 Comm: syz-executor.1 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x19/0x60 kernel/kcov.c:197
Code: 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 48 8b 14 25 c0 fe 01 00 65 8b 05 30 c0 8b 7e a9 00 01 ff 00 48 8b 34 24 <74> 0f f6 c4 01 74 35 8b 82 2c 14 00 00 85 c0 74 2b 8b 82 08 14 00
RSP: 0018:ffffc9001a617848 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 0000000000000050 RCX: ffffffff83f00a74
RDX: ffff8880a8d4c440 RSI: ffffffff83f00a60 RDI: 0000000000000004
RBP: 000000000000003f R08: 0000000000000001 R09: ffff8882184ff91f
R10: 0000000000000050 R11: 0000000000000000 R12: ffff8880000a003f
R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000070c59e32
FS:  00007f1ca6f7c700(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f40c2270000 CR3: 000000020ea65000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 writeb arch/x86/include/asm/io.h:65 [inline]
 vga16fb_fillrect+0x9c0/0x193b drivers/video/fbdev/vga16fb.c:923
 bit_clear_margins+0x2d5/0x4b0 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x1f1/0x280 drivers/video/fbdev/core/fbcon.c:1327
 fbcon_switch+0xafe/0x16b0 drivers/video/fbdev/core/fbcon.c:2191
 redraw_screen+0x2b9/0x790 drivers/tty/vt/vt.c:1020
 fbcon_modechanged+0x593/0x6d0 drivers/video/fbdev/core/fbcon.c:2702
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:2747
 do_fb_ioctl+0x62e/0x690 drivers/video/fbdev/core/fbmem.c:1106
 fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1181
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e179
Code: 3d b2 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 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1ca6f7bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000e280 RCX: 000000000045e179
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffc87a1bbff R14: 00007f1ca6f7c9c0 R15: 000000000118cf4c

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/09/24 12:29 upstream c9c9e6a49f89 54289b08 .config console log report info ci-upstream-kasan-gce-root
* Struck through repros no longer work on HEAD.