INFO: task hung in sock_do_ioctl

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 7472c402 Linux 4.19.108
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13697d53e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=6d889e71eea7bde
dashboard link: https://syzkaller.appspot.com/bug?extid=f16746537fa8f92de55b
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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+f16746...@syzkaller.appspotmail.com

batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
INFO: task syz-executor.2:17690 blocked for more than 140 seconds.
Not tainted 4.19.108-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2 D28416 17690 8211 0x00000004
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3559
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
sock_do_ioctl+0x24e/0x2f0 net/socket.c:963
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c4a9
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:00007f02213bdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f02213be6d4 RCX: 000000000045c4a9
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000006
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000040e R14: 00000000004c6745 R15: 000000000076bf2c
INFO: task syz-executor.3:17905 blocked for more than 140 seconds.
Not tainted 4.19.108-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D29552 17905 8214 0x00000004
Call Trace:
schedule+0x8d/0x1b0 kernel/sched/core.c:3559
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
sock_do_ioctl+0x24e/0x2f0 net/socket.c:963
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c4a9
Code: Bad RIP value.
RSP: 002b:00007fe361489c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe36148a6d4 RCX: 000000000045c4a9
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000006
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000040e R14: 00000000004c6745 R15: 000000000076bf2c

Showing all locks held in the system:
1 lock held by khungtaskd/1080:
#0: 00000000d33a12bd (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4436
1 lock held by udevd/3770:
1 lock held by rsyslogd/8038:
#0: 00000000fb10eb63 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767
2 locks held by getty/8160:
#0: 0000000059b968bd (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 0000000072efe9c0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by getty/8161:
#0: 000000004d203442 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 000000007dfcf4d7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by getty/8162:
#0: 000000001841aa3d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 0000000091e91da1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by getty/8163:
#0: 000000006ad3ffee (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 0000000075c0354d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by getty/8164:
#0: 0000000092757edb (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 000000002ecb5719 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by getty/8165:
#0: 0000000073334582 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 000000006deffdac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
2 locks held by getty/8166:
#0: 00000000061b8664 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 00000000aafc666a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154
4 locks held by kworker/u4:7/9075:
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000adaeb1d8 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2124
#1: 000000007610469f (net_cleanup_work){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2128
#2: 00000000679249f5 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x850 net/core/net_namespace.c:520
#3: 00000000bbe620e7 (rtnl_mutex){+.+.}, at: ip6gre_exit_batch_net+0x88/0x6f0 net/ipv6/ip6_gre.c:1620
3 locks held by kworker/1:2/18105:
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000ee8ca549 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2124
#1: 0000000029a46c2c ((addr_chk_work).work){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2128
#2: 00000000bbe620e7 (rtnl_mutex){+.+.}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4466
3 locks held by kworker/1:1/28792:
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2124
#1: 00000000e77760f9 (deferred_process_work){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2128
#2: 00000000bbe620e7 (rtnl_mutex){+.+.}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
3 locks held by kworker/1:3/28794:
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 0000000083f56809 ((wq_completion)"events"){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2124
#1: 000000001087c48a ((linkwatch_work).work){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2128
#2: 00000000bbe620e7 (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236
1 lock held by syz-executor.2/17690:
#0: 00000000bbe620e7 (rtnl_mutex){+.+.}, at: sock_do_ioctl+0x24e/0x2f0 net/socket.c:963
3 locks held by syz-executor.1/17694:
1 lock held by syz-executor.3/17905:
#0: 00000000bbe620e7 (rtnl_mutex){+.+.}, at: sock_do_ioctl+0x24e/0x2f0 net/socket.c:963

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

NMI backtrace for cpu 0
CPU: 0 PID: 1080 Comm: khungtaskd Not tainted 4.19.108-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+0x188/0x20d lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
watchdog+0x962/0xe40 kernel/hung_task.c:287
kthread+0x34a/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 17694 Comm: syz-executor.1 Not tainted 4.19.108-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0x3b6/0x49c0 kernel/locking/lockdep.c:3353
Code: 49 8d 7a 08 48 89 fa 48 c1 ea 03 66 25 00 e0 09 c8 66 41 89 42 20 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 2a 2e 00 00 <48> 8b 45 18 49 8d 7a 10 48 89 fa 48 c1 ea 03 49 89 42 08 48 b8 00
RSP: 0018:ffff88804524e8a0 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000526
RDX: 1ffff110152579d6 RSI: 1ffff110152579d4 RDI: ffff8880a92bceb0
RBP: ffff88804524ea70 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8880a92bcea8 R11: 0000000000000526 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880a92bc600 R15: ffffffff896c0fd8
FS: 00007f5a64a05700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002426000 CR3: 000000008cd76000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3903
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
addrconf_ifdown+0x1f7/0x10f0 net/ipv6/addrconf.c:3692
addrconf_notify+0x5cd/0x2160 net/ipv6/addrconf.c:3579
notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
call_netdevice_notifiers net/core/dev.c:1766 [inline]
__dev_notify_flags+0x1e9/0x2c0 net/core/dev.c:7703
dev_change_flags+0xf0/0x140 net/core/dev.c:7737
do_setlink+0x1601/0x3510 net/core/rtnetlink.c:2449
rtnl_group_changelink net/core/rtnetlink.c:2925 [inline]
rtnl_newlink+0xc7e/0x1440 net/core/rtnetlink.c:3083
rtnetlink_rcv_msg+0x453/0xaf0 net/core/rtnetlink.c:4777
netlink_rcv_skb+0x160/0x410 net/netlink/af_netlink.c:2455
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x4d7/0x6a0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x80b/0xcd0 net/netlink/af_netlink.c:1909
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:632
___sys_sendmsg+0x803/0x920 net/socket.c:2115
__sys_sendmsg+0xec/0x1b0 net/socket.c:2153
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c4a9
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:00007f5a64a04c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5a64a056d4 RCX: 000000000045c4a9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000009f9 R14: 00000000004cc766 R15: 000000000076bf2c


---
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[syzbot]

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