INFO: task hung in paste_selection (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2d2791fc Linux 4.14.217
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=160d7e44d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=80753487c013c9c7
dashboard link: https://syzkaller.appspot.com/bug?extid=f3d9445013d9f4e2f262
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f3d944...@syzkaller.appspotmail.com

team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
INFO: task syz-executor.5:31863 blocked for more than 140 seconds.
Not tainted 4.14.217-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D29672 31863 29764 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373
tioclinux+0xfd/0x490 drivers/tty/vt/vt.c:2714
vt_ioctl+0x11bd/0x1d50 drivers/tty/vt/vt_ioctl.c:372
tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45e219
RSP: 002b:00007f2d5e4f6c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000004
RBP: 000000000119c110 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c0dc
R13: 00007ffd3c31422f R14: 00007f2d5e4f79c0 R15: 000000000119c0dc
INFO: task syz-executor.5:31889 blocked for more than 140 seconds.
Not tainted 4.14.217-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D29672 31889 29764 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373
tioclinux+0xfd/0x490 drivers/tty/vt/vt.c:2714
vt_ioctl+0x11bd/0x1d50 drivers/tty/vt/vt_ioctl.c:372
tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45e219
RSP: 002b:00007f2d5e4d5c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000005
RBP: 000000000119c1b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c184
R13: 00007ffd3c31422f R14: 00007f2d5e4d69c0 R15: 000000000119c184
INFO: task syz-executor.4:31885 blocked for more than 140 seconds.
Not tainted 4.14.217-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D28880 31885 10085 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2808 [inline]
__schedule+0x88b/0x1de0 kernel/sched/core.c:3384
schedule+0x8d/0x1b0 kernel/sched/core.c:3428
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
__mutex_lock_common kernel/locking/mutex.c:833 [inline]
__mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893
paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373
tioclinux+0xfd/0x490 drivers/tty/vt/vt.c:2714
vt_ioctl+0x11bd/0x1d50 drivers/tty/vt/vt_ioctl.c:372
tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45e219
RSP: 002b:00007ff704bbec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000005
RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffca43d60af R14: 00007ff704bbf9c0 R15: 000000000119bf8c

Showing all locks held in the system:
1 lock held by khungtaskd/1529:
#0: (tasklist_lock){.+.+}, at: [<ffffffff86feead7>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by in:imklog/7670:
#0: (&f->f_pos_lock){+.+.}, at: [<ffffffff818d061b>] __fdget_pos+0x1fb/0x2b0 fs/file.c:769
2 locks held by agetty/7694:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8352a583>] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156
2 locks held by agetty/11200:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8352a583>] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156
2 locks held by agetty/12238:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff8352a583>] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.5/31863:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&buf->lock){+.+.}, at: [<ffffffff8355a53e>] paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373
2 locks held by syz-executor.5/31889:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&buf->lock){+.+.}, at: [<ffffffff8355a53e>] paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373
2 locks held by syz-executor.1/31881:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&buf->lock){+.+.}, at: [<ffffffff8355a53e>] paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373
2 locks held by syz-executor.4/31885:
#0: (&tty->ldisc_sem){++++}, at: [<ffffffff83535202>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
#1: (&buf->lock){+.+.}, at: [<ffffffff8355a53e>] paste_selection+0x10e/0x420 drivers/tty/vt/selection.c:373

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

NMI backtrace for cpu 0
CPU: 0 PID: 1529 Comm: khungtaskd Not tainted 4.14.217-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
watchdog+0x5b9/0xb40 kernel/hung_task.c:274
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4624 Comm: systemd-journal Not tainted 4.14.217-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a10c6140 task.stack: ffff8880a1660000
RIP: 0010:__phys_addr_symbol+0x38/0x60 arch/x86/mm/physaddr.c:41
RSP: 0018:ffff8880a1667d58 EFLAGS: 00000246
RAX: 1ffffffff11ce002 RBX: 0000000001000000 RCX: 000000000000000c
RDX: dffffc0000000000 RSI: 0000000000000fe4 RDI: ffffffff81000000
RBP: 0000000000000000 R08: 0000000000000fe4 R09: ffff88805e8403c0
R10: ffff88805e8413bf R11: 0000000000000000 R12: ffff88805e8403dc
R13: ffffea00017a1000 R14: ffff88805e8413c0 R15: ffff888000000000
FS: 00007f0bfa8b58c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0bf5577010 CR3: 00000000a1416000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
check_kernel_text_object mm/usercopy.c:109 [inline]
__check_object_size mm/usercopy.c:265 [inline]
__check_object_size+0x158/0x230 mm/usercopy.c:228
check_object_size include/linux/thread_info.h:108 [inline]
strncpy_from_user+0x89/0x2c0 lib/strncpy_from_user.c:117
getname_flags+0x10d/0x550 fs/namei.c:149
user_path_at_empty+0x2a/0x50 fs/namei.c:2631
user_path_at include/linux/namei.h:57 [inline]
SYSC_faccessat fs/open.c:403 [inline]
SyS_faccessat+0x21b/0x680 fs/open.c:353
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f0bf9b719c7
RSP: 002b:00007ffcb20563f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffcb2059310 RCX: 00007f0bf9b719c7
RDX: 00007f0bfa5e2a00 RSI: 0000000000000000 RDI: 00005652c4f169a3
RBP: 00007ffcb2056430 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffcb2059310 R15: 00007ffcb2056920
Code: 80 48 01 c3 48 81 fb ff ff ff 1f 77 2c e8 41 26 30 00 48 c7 c0 10 00 e7 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <75> 13 48 8b 05 cf 00 c2 07 48 01 d8 5b c3 e8 15 26 30 00 0f 0b


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.