syzbot


INFO: task hung in console_callback

Status: auto-closed as invalid on 2020/05/10 04:25
Reported-by: syzbot+70b8b89b29e2035a631e@syzkaller.appspotmail.com
First crash: 1778d, last: 1778d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in console_callback serial 7 1599d 1767d 0/28 closed as dup on 2020/08/16 15:22
upstream INFO: task hung in console_callback (2) serial 1 992d 992d 0/28 auto-closed as invalid on 2022/06/05 01:15
linux-4.14 INFO: task hung in console_callback 1 1706d 1706d 0/1 auto-closed as invalid on 2020/07/20 15:40
linux-4.19 INFO: task hung in console_callback (2) 1 1463d 1463d 0/1 auto-closed as invalid on 2021/03/20 18:26
upstream INFO: task hung in console_callback (4) serial 65 419d 426d 0/28 auto-obsoleted due to no activity on 2023/12/09 22:03
upstream INFO: task hung in console_callback (3) serial 11 821d 866d 0/28 auto-obsoleted due to no activity on 2022/11/22 14:53

Sample crash report:
F2FS-fs (loop2): Can't find valid F2FS filesystem in 2th superblock
IPVS: ftp: loaded support on port[0] = 21
netlink: 104 bytes leftover after parsing attributes in process `syz-executor.2'.
IPVS: ftp: loaded support on port[0] = 21
INFO: task kworker/0:2:2838 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:2     D26384  2838      2 0x80000000
Workqueue: events console_callback
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
 console_callback+0x70/0x400 drivers/tty/vt/vt.c:2794
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Showing all locks held in the system:
1 lock held by khungtaskd/1082:
 #0: 000000001f2e766d (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
2 locks held by kworker/0:2/2838:
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000c3244b1a ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
 #1: 0000000007935622 (console_work){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
1 lock held by rsyslogd/7805:
 #0: 00000000f8bd5093 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/7927:
 #0: 00000000634b2a52 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000bf2afe0b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7928:
 #0: 000000003313db31 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000ebbfdbb6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7929:
 #0: 0000000066c0c0e9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000000bb391ab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7930:
 #0: 000000007e18755c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000009d315f7d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7931:
 #0: 00000000671c3029 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000f1c1ebc0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7932:
 #0: 00000000641be2e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000006f0e043d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7933:
 #0: 00000000c220f7d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000a24e2310 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
3 locks held by syz-executor.1/15797:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1082 Comm: khungtaskd Not tainted 4.19.94-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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15797 Comm: syz-executor.1 Not tainted 4.19.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:101
Code: 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 08 d8 96 7e 81 e2 00 01 1f 00 75 2b <8b> 90 d0 12 00 00 83 fa 02 75 20 48 8b 88 d8 12 00 00 8b 80 d4 12
RSP: 0018:ffff888046177150 EFLAGS: 00000246
RAX: ffff888046e546c0 RBX: 0000000000000000 RCX: ffffffff838b3798
RDX: 0000000000000000 RSI: ffffffff838b3780 RDI: 0000000000000005
RBP: ffff888046177150 R08: ffff888046e546c0 R09: 0000000000000040
R10: ffffed10432cb12b R11: ffff88821965895f R12: 0000000000000000
R13: ffff8880000a00e8 R14: ffff8880000a00c0 R15: 0000000000000005
FS:  00007f6e65b4e700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c432c43e50 CR3: 000000008825d000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:75 [inline]
 bitfill_aligned+0x180/0x210 drivers/video/fbdev/core/cfbfillrect.c:35
 cfb_fillrect+0x423/0x7c0 drivers/video/fbdev/core/cfbfillrect.c:327
 vga16fb_fillrect+0x6ce/0x19b0 drivers/video/fbdev/vga16fb.c:951
 bit_clear_margins+0x30b/0x530 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x2e3/0x370 drivers/video/fbdev/core/fbcon.c:1339
 fbcon_switch+0xe7d/0x1a40 drivers/video/fbdev/core/fbcon.c:2321
 redraw_screen+0x37d/0x8e0 drivers/tty/vt/vt.c:997
 fbcon_modechanged+0x5f3/0x900 drivers/video/fbdev/core/fbcon.c:2969
 fbcon_event_notify+0x1bd/0x1dba drivers/video/fbdev/core/fbcon.c:3344
 notifier_call_chain+0xc2/0x230 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+0x94/0xb0 kernel/notifier.c:325
 fb_notifier_call_chain+0x25/0x30 drivers/video/fbdev/core/fb_notify.c:45
 fb_set_var+0xc8f/0xe80 drivers/video/fbdev/core/fbmem.c:1042
 do_fb_ioctl+0x450/0xab0 drivers/video/fbdev/core/fbmem.c:1115
 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1230
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
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:00007f6e65b4dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 00000000200001c0 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6e65b4e6d4
R13: 00000000004c3903 R14: 00000000004d9f18 R15: 00000000ffffffff

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/11 04:24 linux-4.19.y cb1f9a169a0e 4c04afaa .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.