INFO: task hung in ipv6_route_ioctl

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13f82326b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=ace33c71a8ac26c3f6db
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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+ace33c...@syzkaller.appspotmail.com

batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
INFO: task syz-executor.5:6401 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D29456 6401 678 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
__mutex_lock_common kernel/locking/mutex.c:1016 [inline]
__mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
ipv6_route_ioctl+0x21a/0x2f0 net/ipv6/route.c:3725
inet6_ioctl+0x104/0x1b0 net/ipv6/af_inet6.c:559
sock_do_ioctl+0xce/0x300 net/socket.c:1015
sock_ioctl+0x2ef/0x5d0 net/socket.c:1135
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xcdb/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: 0033:0x7f0183c4eae9
Code: Bad RIP value.
RSP: 002b:00007f01811a3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0183d62020 RCX: 00007f0183c4eae9
RDX: 00000000200002c0 RSI: 000000000000890c RDI: 0000000000000004
RBP: 00007f0183ca8f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff28e821ef R14: 00007f01811a3300 R15: 0000000000022000

Showing all locks held in the system:
4 locks held by kworker/u4:0/7:
#0: 00000000814249ed ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 00000000340944ee (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 000000003f73b468 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521
#3: 0000000090fd80cf (rtnl_mutex){+.+.}, at: cangw_pernet_exit+0xe/0x20 net/can/gw.c:1032
2 locks held by kworker/u4:1/23:
3 locks held by kworker/1:1/33:
#0: 00000000198e9b5e ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 00000000e6499ee9 ((addr_chk_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 0000000090fd80cf (rtnl_mutex){+.+.}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4476
1 lock held by khungtaskd/1570:
#0: 0000000000d3d4f0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
3 locks held by kworker/0:2/3586:
#0: 00000000f28916eb ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 00000000d9e51141 (deferred_process_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 0000000090fd80cf (rtnl_mutex){+.+.}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
1 lock held by in:imklog/7799:
#0: 000000006ac1dac6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by agetty/8020:
#0: 000000001aa2a072 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272
#1: 000000003ee0a062 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154
3 locks held by kworker/u4:8/18129:
#0: 00000000879663be ((wq_completion)"cfg80211"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 000000005031b997 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 0000000090fd80cf (rtnl_mutex){+.+.}, at: cfg80211_dfs_channels_update_work+0x98/0x5a0 net/wireless/mlme.c:777
3 locks held by kworker/1:2/22760:
#0: 00000000f28916eb ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
#1: 00000000134b60ac ((linkwatch_work).work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128
#2: 0000000090fd80cf (rtnl_mutex){+.+.}, at: linkwatch_event+0xb/0x60 net/core/link_watch.c:236
2 locks held by syz-executor.1/6341:
1 lock held by syz-executor.5/6401:
#0: 0000000090fd80cf (rtnl_mutex){+.+.}, at: ipv6_route_ioctl+0x21a/0x2f0 net/ipv6/route.c:3725
1 lock held by syz-executor.5/6403:
#0: 0000000090fd80cf (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
#0: 0000000090fd80cf (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779

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

NMI backtrace for cpu 1
CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-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+0x1fc/0x2ef lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 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+0x991/0xe60 kernel/hung_task.c:287
kthread+0x33f/0x460 kernel/kthread.c:259
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: 6341 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:lock_acquire+0x1ec/0x3c0 kernel/locking/lockdep.c:3911
Code: 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 b7 01 00 00 48 83 3d 09 2e a6 08 00 0f 84 2a 01 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 65 8b
RSP: 0018:ffff8880ba007e58 EFLAGS: 00000086
RAX: 1ffffffff13e3051 RBX: ffff88809ed90440 RCX: 0000000000004ca4
RDX: dffffc0000000000 RSI: 00000000ea93c406 RDI: 0000000000000086
RBP: ffffffff89f95488 R08: ffffffff8cd3da60 R09: 0000000000000002
R10: ffff88809ed90d18 R11: ffffffff8c66501b R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000001
FS: 00007f1045d29700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0fd3e5e000 CR3: 0000000096c6c000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline]
read_seqcount_begin include/linux/seqlock.h:164 [inline]
ktime_get_update_offsets_now+0xcd/0x460 kernel/time/timekeeping.c:2225
hrtimer_update_base kernel/time/hrtimer.c:621 [inline]
hrtimer_interrupt+0x449/0x9e0 kernel/time/hrtimer.c:1617
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1071 [inline]
smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1096
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
</IRQ>
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0xe0 kernel/rcu/update.c:253
Code: ff ff 48 89 ef e8 90 c4 47 00 e9 fa fd ff ff 48 89 ef e8 83 c4 47 00 e9 62 fe ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> c7 c0 44 e0 26 8b 53 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83
RSP: 0018:ffff88803cdeeb60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 00000000ffffffff RDI: 0000000000000286
RBP: ffffffff8950efc0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000774
R13: 000000000000b06f R14: 0000000000000000 R15: 0000000000000001
___might_sleep+0x2b/0x2b0 kernel/sched/core.c:6157
get_next_corpse net/netfilter/nf_conntrack_core.c:1908 [inline]
nf_ct_iterate_cleanup+0x24c/0x520 net/netfilter/nf_conntrack_core.c:1930
nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2015 [inline]
nf_ct_iterate_cleanup_net+0x113/0x170 net/netfilter/nf_conntrack_core.c:2000
masq_device_event+0xae/0xe0 net/ipv6/netfilter/nf_nat_masquerade_ipv6.c:77
notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
call_netdevice_notifiers net/core/dev.c:1762 [inline]
__dev_notify_flags+0x1da/0x2b0 net/core/dev.c:7719
dev_change_flags+0xf0/0x140 net/core/dev.c:7753
do_setlink+0x14f1/0x3540 net/core/rtnetlink.c:2449
rtnl_group_changelink net/core/rtnetlink.c:2925 [inline]
rtnl_newlink+0xbc9/0x15c0 net/core/rtnetlink.c:3083
rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782
netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463
netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline]
netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351
netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0xc3/0x120 net/socket.c:661
___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227
__sys_sendmsg net/socket.c:2265 [inline]
__do_sys_sendmsg net/socket.c:2274 [inline]
__se_sys_sendmsg net/socket.c:2272 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2272
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f10487d4ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1045d29188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f10488e8020 RCX: 00007f10487d4ae9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00007f104882ef6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcf7dc7a6f R14: 00007f1045d29300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: 08 00 or %al,(%rax)
2: 00 00 add %al,(%rax)
4: 00 00 add %al,(%rax)
6: 00 48 c1 add %cl,-0x3f(%rax)
9: e8 03 80 3c 10 callq 0x103c8011
e: 00 0f add %cl,(%rdi)
10: 85 b7 01 00 00 48 test %esi,0x48000001(%rdi)
16: 83 3d 09 2e a6 08 00 cmpl $0x0,0x8a62e09(%rip) # 0x8a62e26
1d: 0f 84 2a 01 00 00 je 0x14d
23: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi
28: 57 push %rdi
29: 9d popfq
* 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction
2f: 48 83 c4 18 add $0x18,%rsp
33: 5b pop %rbx
34: 5d pop %rbp
35: 41 5c pop %r12
37: 41 5d pop %r13
39: 41 5e pop %r14
3b: 41 5f pop %r15
3d: c3 retq
3e: 65 gs
3f: 8b .byte 0x8b


---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status 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.