Subject: [syzbot] [net?] INFO: task hung in addrconf_dad_work (5)

From: syzbot <[email-masked]>
Date: Mon, 29 Jul 2024 08:23:23 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    dc1c8034e31b minmax: simplify min()/max()/clamp() implemen..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=135baf03980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8b0cca2f3880513d
dashboard link: https://syzkaller.appspot.com/bug?extid=82ccd564344eeaa5427d
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/29a310f3ad21/disk-dc1c8034.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4d35d3afb396/vmlinux-dc1c8034.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed329ce5166e/bzImage-dc1c8034.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

INFO: task kworker/u8:2:35 blocked for more than 143 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00004-gdc1c8034e31b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:20272 pid:35    tgid:35    ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4194
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task dhcpcd:4884 blocked for more than 144 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00004-gdc1c8034e31b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:21632 pid:4884  tgid:4884  ppid:1      flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 genl_lock net/netlink/genetlink.c:35 [inline]
 genl_op_lock net/netlink/genetlink.c:60 [inline]
 genl_rcv_msg+0x121/0xec0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f2/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
 ___sys_sendmsg net/socket.c:2651 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa250dd6a4b
RSP: 002b:00007fff5e4c9d68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00005616070a494f RCX: 00007fa250dd6a4b
RDX: 0000000000000000 RSI: 00007fff5e4c9db0 RDI: 0000000000000010
RBP: 00007fff5e4ce8a8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000010
R13: 00007fff5e4cde10 R14: 0000000000000000 R15: 0000561624964ba0
 </TASK>
INFO: task kworker/1:11:6096 blocked for more than 146 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00004-gdc1c8034e31b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:11    state:D
 stack:19768 pid:6096  tgid:6096  ppid:2      flags:0x00004000
Workqueue: events linkwatch_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 linkwatch_event+0xe/0x60 net/core/link_watch.c:276
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task kworker/1:0:9989 blocked for more than 148 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00004-gdc1c8034e31b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:21208 pid:9989  tgid:9989  ppid:2      flags:0x00004000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor:12923 blocked for more than 149 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00004-gdc1c8034e31b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:20992 pid:12923 tgid:12923 ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 rtnl_lock net/core/rtnetlink.c:79 [inline]
 rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f2/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2204
 __do_sys_sendto net/socket.c:2216 [inline]
 __se_sys_sendto net/socket.c:2212 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2212
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f365877902c
RSP: 002b:00007ffd4ffb8c30 EFLAGS: 00000293
 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f3659434620 RCX: 00007f365877902c
RDX: 0000000000000020 RSI: 00007f3659434670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd4ffb8c84 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f3659434670 R15: 0000000000000000
 </TASK>
INFO: task syz-executor:13157 blocked for more than 151 seconds.
      Not tainted 6.11.0-rc1-syzkaller-00004-gdc1c8034e31b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:19152 pid:13157 tgid:13157 ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 wg_set_device+0x102/0x2160 drivers/net/wireguard/netlink.c:504
 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0xb16/0xec0 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2550
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f2/0x990 net/netlink/af_netlink.c:1357

---
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