INFO: task hung in dev_ioctl

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: a880148cb2af Add linux-next specific files for 20180831
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14e6710a400000
kernel config: https://syzkaller.appspot.com/x/.config?x=a059d319ef7d83f6
dashboard link: https://syzkaller.appspot.com/bug?extid=6feaba18324aebd1eca0
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [christia...@ubuntu.com da...@davemloft.net
dsa...@gmail.com f...@strlen.de jakub.k...@netronome.com
jb...@redhat.com ktk...@virtuozzo.com linux-...@vger.kernel.org
lucie...@gmail.com net...@vger.kernel.org nicolas...@6wind.com]

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6feaba...@syzkaller.appspotmail.com

loop5: rw=12288, want=12296, limit=20
attempt to access beyond end of device
loop5: rw=12288, want=8200, limit=20
attempt to access beyond end of device
loop5: rw=12288, want=12296, limit=20
INFO: task syz-executor3:12274 blocked for more than 140 seconds.
Not tainted 4.19.0-rc1-next-20180831+ #53
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3 D25640 12274 4703 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
dev_ioctl+0x1a8/0xcc0 net/core/dev_ioctl.c:487
sock_do_ioctl+0x1d3/0x3e0 net/socket.c:973
sock_ioctl+0x30d/0x680 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48
89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48
8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74
RSP: 002b:00007f1760bf5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1760bf66d4 RCX: 0000000000457099
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000008
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d2598 R14: 00000000004c799c R15: 0000000000000001
INFO: task syz-executor2:12276 blocked for more than 140 seconds.
Not tainted 4.19.0-rc1-next-20180831+ #53
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2 D24712 12276 4701 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
__netlink_dump_start+0x107/0x6f0 net/netlink/af_netlink.c:2296
netlink_dump_start include/linux/netlink.h:213 [inline]
rtnetlink_rcv_msg+0x811/0xc30 net/core/rtnetlink.c:4678
netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4733
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343
netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:632
___sys_sendmsg+0x7fd/0x930 net/socket.c:2115
__sys_sendmsg+0x11d/0x290 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48
89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48
8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74
RSP: 002b:00007fc2fea3dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc2fea3e6d4 RCX: 0000000000457099
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d44b8 R14: 00000000004c8b62 R15: 0000000000000001
INFO: task syz-executor2:12339 blocked for more than 140 seconds.
Not tainted 4.19.0-rc1-next-20180831+ #53
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2 D24712 12339 4701 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
__netlink_dump_start+0x107/0x6f0 net/netlink/af_netlink.c:2296
netlink_dump_start include/linux/netlink.h:213 [inline]
rtnetlink_rcv_msg+0x811/0xc30 net/core/rtnetlink.c:4678
netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4733
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343
netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xd5/0x120 net/socket.c:632
___sys_sendmsg+0x7fd/0x930 net/socket.c:2115
__sys_sendmsg+0x11d/0x290 net/socket.c:2153
__do_sys_sendmsg net/socket.c:2162 [inline]
__se_sys_sendmsg net/socket.c:2160 [inline]
__x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48
89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48
8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74
RSP: 002b:00007fc2fe9fbc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc2fe9fc6d4 RCX: 0000000000457099
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 0000000000930280 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d44b8 R14: 00000000004c8b62 R15: 0000000000000003
INFO: task syz-executor1:12279 blocked for more than 140 seconds.
Not tainted 4.19.0-rc1-next-20180831+ #53
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D25408 12279 4702 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
sock_do_ioctl+0x2ba/0x3e0 net/socket.c:963
sock_ioctl+0x30d/0x680 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48
89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48
8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74
RSP: 002b:00007fab1e5a9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fab1e5aa6d4 RCX: 0000000000457099
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000004
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cfaa8 R14: 00000000004c5ce3 R15: 0000000000000000
INFO: task syz-executor1:12286 blocked for more than 140 seconds.
Not tainted 4.19.0-rc1-next-20180831+ #53
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1 D23392 12286 4702 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x87c/0x1df0 kernel/sched/core.c:3473
schedule+0xfb/0x450 kernel/sched/core.c:3517
schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1003 [inline]
__mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
sock_do_ioctl+0x2ba/0x3e0 net/socket.c:963
sock_ioctl+0x30d/0x680 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
__do_sys_ioctl fs/ioctl.c:709 [inline]
__se_sys_ioctl fs/ioctl.c:707 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48
89 04 24 48 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 <8b> 4c 24 48 48
8b 54 24 38 4c 8b 54 24 18 e9 ee fe ff ff 48 89 74
RSP: 002b:00007fab1e588c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fab1e5896d4 RCX: 0000000000457099
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000009
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cfaa8 R14: 00000000004c5ce3 R15: 0000000000000001

Showing all locks held in the system:
3 locks held by kworker/0:0/5:
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
__write_once_size include/linux/compiler.h:215 [inline]
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_data kernel/workqueue.c:617 [inline]
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 0000000030f928c0 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124
#1: 00000000811b8144 ((addr_chk_work).work){+.+.}, at:
process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128
#2: 00000000075ed192 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by khungtaskd/791:
#0: 00000000564d61bd (rcu_read_lock){....}, at:
debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436
1 lock held by rsyslogd/4564:
#0: 0000000007f7d252 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200
fs/file.c:766
2 locks held by getty/4655:
#0: 00000000ce3b03c6 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000007bb7f17d (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4656:
#0: 00000000b6c3dbd7 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000da18f537 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4657:
#0: 00000000fd18e5c3 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000006a5d00a9 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4658:
#0: 00000000d88715b4 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000009a98b5c7 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4659:
#0: 000000006085f0f9 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000a0e92a66 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4660:
#0: 00000000bf1601ce (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000000f1e0ae9 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4661:
#0: 00000000c1548013 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000106acca0 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
1 lock held by syz-executor3/12260:
1 lock held by syz-executor3/12274:
#0: 00000000075ed192 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor2/12276:
#0: 00000000075ed192 (rtnl_mutex){+.+.}, at:
__netlink_dump_start+0x107/0x6f0 net/netlink/af_netlink.c:2296
1 lock held by syz-executor2/12339:
#0: 00000000075ed192 (rtnl_mutex){+.+.}, at:
__netlink_dump_start+0x107/0x6f0 net/netlink/af_netlink.c:2296
1 lock held by syz-executor1/12279:
#0: 00000000075ed192 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor1/12286:
#0: 00000000075ed192 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77

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

NMI backtrace for cpu 1
CPU: 1 PID: 791 Comm: khungtaskd Not tainted 4.19.0-rc1-next-20180831+ #53
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+0x1c9/0x2b4 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x151/0x192 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:144 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
watchdog+0xb39/0x1040 kernel/hung_task.c:265
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10
arch/x86/include/asm/irqflags.h:56


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

[syzbot]

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