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INFO: task hung in console_callback

Status: closed as dup on 2020/08/16 15:22
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+2cc8ec111ca094cf3fb7@syzkaller.appspotmail.com
First crash: 1565d, last: 1393d
▶ ▼ Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
KASAN: vmalloc-out-of-bounds Write in bitfill_aligned fbdev C 475 1375d 1609d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
INFO: task hung in console_callback 0 (1) 2020/01/22 09:55
▶ ▼ Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in console_callback (2) serial 1 786d 786d 0/26 auto-closed as invalid on 2022/06/05 01:15
linux-4.14 INFO: task hung in console_callback 1 1501d 1501d 0/1 auto-closed as invalid on 2020/07/20 15:40
linux-4.19 INFO: task hung in console_callback (2) 1 1258d 1258d 0/1 auto-closed as invalid on 2021/03/20 18:26
upstream INFO: task hung in console_callback (4) serial 65 213d 220d 0/26 auto-obsoleted due to no activity on 2023/12/09 22:03
upstream INFO: task hung in console_callback (3) serial 11 616d 660d 0/26 auto-obsoleted due to no activity on 2022/11/22 14:53
linux-4.19 INFO: task hung in console_callback 1 1572d 1572d 0/1 auto-closed as invalid on 2020/05/10 04:25

Sample crash report:
INFO: task kworker/1:4:2496 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:4     D23728  2496      2 0x00004000
Workqueue: events console_callback
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1873
 __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:2309
 console_callback+0x61/0x410 drivers/tty/vt/vt.c:2844
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
INFO: task syz-executor.4:27830 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28240 27830   7343 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 lock_fb_info include/linux/fb.h:637 [inline]
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 __do_sys_openat fs/open.c:1209 [inline]
 __se_sys_openat fs/open.c:1204 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1204
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007fd9f24dfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f86e0 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007c1 R14: 00000000004caafb R15: 00007fd9f24e06d4
INFO: task syz-executor.1:27903 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28240 27903   6956 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1873
 __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:2309
 do_con_write+0x11e/0x7400 drivers/tty/vt/vt.c:2596
 con_write+0x22/0xb0 drivers/tty/vt/vt.c:3159
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0x3ce/0xf80 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:962 [inline]
 tty_write+0x4d9/0x870 drivers/tty/tty_io.c:1046
 __vfs_write+0x76/0x100 fs/read_write.c:495
 vfs_write+0x268/0x5d0 fs/read_write.c:559
 ksys_write+0x12d/0x250 fs/read_write.c:612
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f83ae2bcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000050df60 RCX: 000000000045cb29
RDX: 0000000000001006 RSI: 0000000020002080 RDI: 0000000000000007
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000d23 R14: 00000000004cf7c7 R15: 00007f83ae2bd6d4

Showing all locks held in the system:
1 lock held by khungtaskd/1148:
 #0: ffffffff89bc1180 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779
2 locks held by kworker/1:4/2496:
 #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff8880aa026d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc90007e9fda8 (console_work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
1 lock held by in:imklog/6549:
 #0: ffff8880a6c56930 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
4 locks held by login/6732:
 #0: ffff8880a196f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffff8880a196f130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:888 [inline]
 #1: ffff8880a196f130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:911 [inline]
 #1: ffff8880a196f130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write+0x280/0x870 drivers/tty/tty_io.c:1046
 #2: ffff8880a196f2e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_write+0x1bf/0xf80 drivers/tty/n_tty.c:2316
 #3: ffffc90000fa4378 (&ldata->output_lock){+.+.}-{3:3}, at: process_output_block drivers/tty/n_tty.c:550 [inline]
 #3: ffffc90000fa4378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0x4fa/0xf80 drivers/tty/n_tty.c:2333
2 locks held by syz-executor.4/27824:
1 lock held by syz-executor.4/27830:
 #0: ffff8882188b7078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline]
 #0: ffff8882188b7078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418
4 locks held by syz-executor.1/27903:
 #0: ffff88809a0fd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267
 #1: ffff88809a0fd130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:888 [inline]
 #1: ffff88809a0fd130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: do_tty_write drivers/tty/tty_io.c:911 [inline]
 #1: ffff88809a0fd130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write+0x280/0x870 drivers/tty/tty_io.c:1046
 #2: ffff88809a0fd2e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_write+0x1bf/0xf80 drivers/tty/n_tty.c:2316
 #3: ffffc90000fc4378 (&ldata->output_lock){+.+.}-{3:3}, at: process_output_block drivers/tty/n_tty.c:550 [inline]
 #3: ffffc90000fc4378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_write+0x4fa/0xf80 drivers/tty/n_tty.c:2333

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

NMI backtrace for cpu 0
CPU: 0 PID: 1148 Comm: khungtaskd Not tainted 5.8.0-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+0x18f/0x20d 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:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 27824 Comm: syz-executor.4 Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:write_comp_data+0x2f/0x80 kernel/kcov.c:218
Code: 05 16 4c 8e 7e 65 48 8b 34 25 00 ff 01 00 a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 86 04 14 00 00 85 c0 74 4f 8b 86 e0 13 00 00 <83> f8 03 75 44 48 8b 86 e8 13 00 00 8b b6 e4 13 00 00 4c 8b 00 48
RSP: 0018:ffffc900022d75a8 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000050 RCX: ffffffff83c646a4
RDX: 000000000000001e RSI: ffff8880406ae140 RDI: 0000000000000004
RBP: 000000000000001e R08: 0000000000000001 R09: ffff88821887a75f
R10: 0000000000000050 R11: 0000000000000000 R12: ffff8880000a001e
R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000ef48cf99
FS:  00007fd9f2501700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0004bc0a4 CR3: 00000000a1d76000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vga16fb_fillrect+0x9d4/0x193b drivers/video/fbdev/vga16fb.c:922
 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x1d5/0x230 drivers/video/fbdev/core/fbcon.c:1381
 fbcon_switch+0xb6e/0x16c0 drivers/video/fbdev/core/fbcon.c:2363
 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1015
 fbcon_modechanged+0x575/0x710 drivers/video/fbdev/core/fbcon.c:3001
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007fd9f2500c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e55e0 RCX: 000000000045cb29
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000006
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002fd R14: 00000000004c58a5 R15: 00007fd9f25016d4

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/07/08 02:45 upstream 7cc2a8ea1048 51095195 .config console log report ci-upstream-kasan-gce
2020/07/07 00:24 upstream 7cc2a8ea1048 51095195 .config console log report ci-upstream-kasan-gce
2020/07/01 22:05 upstream 7c30b859a947 39acb39d .config console log report ci-upstream-kasan-gce
2020/05/09 14:29 upstream d5eeab8d7e26 88cb3e92 .config console log report ci-upstream-kasan-gce-smack-root
2020/04/16 19:24 upstream 00086336a8d9 c743fcb3 .config console log report ci-upstream-kasan-gce
2020/01/18 05:11 upstream ab7541c3addd 3de7aabb .config console log report ci-upstream-kasan-gce-selinux-root
2020/07/03 13:27 upstream cd77006e01b3 bed10395 .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.