[moderation] [afs?] [net?] INFO: task hung in rxrpc_destroy_all_connections (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 076d56d74f17 Add linux-next specific files for 20240202
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11ee592fe80000
kernel config: https://syzkaller.appspot.com/x/.config?x=428086ff1c010d9f
dashboard link: https://syzkaller.appspot.com/bug?extid=06cafeeb1fcc989468f0
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [da...@davemloft.net dhow...@redhat.com edum...@google.com ku...@kernel.org linu...@lists.infradead.org linux-...@vger.kernel.org linux-...@vger.kernel.org marc....@auristor.com net...@vger.kernel.org pab...@redhat.com]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/dece45d1a4b5/disk-076d56d7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4921e269b178/vmlinux-076d56d7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2a9156da9091/bzImage-076d56d7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+06cafe...@syzkaller.appspotmail.com

INFO: task syz-executor.0:20178 blocked for more than 144 seconds.
Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:24976 pid:20178 tgid:20174 ppid:15002 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5400 [inline]
__schedule+0x17df/0x4a40 kernel/sched/core.c:6727
__schedule_loop kernel/sched/core.c:6804 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6819
schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
__flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617
rxrpc_destroy_all_connections+0xf0/0x3f0 net/rxrpc/conn_object.c:471
rxrpc_exit_net+0x77/0xc0 net/rxrpc/net_ns.c:113
ops_exit_list net/core/net_namespace.c:170 [inline]
setup_net+0x8d3/0xbc0 net/core/net_namespace.c:362
copy_net_ns+0x4e4/0x7b0 net/core/net_namespace.c:495
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x619/0xc10 kernel/fork.c:3450
__do_sys_unshare kernel/fork.c:3521 [inline]
__se_sys_unshare kernel/fork.c:3519 [inline]
__x64_sys_unshare+0x38/0x40 kernel/fork.c:3519
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f897187dda9
RSP: 002b:00007f89726250c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f89719ac050 RCX: 00007f897187dda9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000
RBP: 00007f89718ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f89719ac050 R15: 00007fffd773cb28
</TASK>
INFO: task syz-executor.2:20253 blocked for more than 144 seconds.
Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2 state:D stack:24976 pid:20253 tgid:20247 ppid:5110 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5400 [inline]
__schedule+0x17df/0x4a40 kernel/sched/core.c:6727
__schedule_loop kernel/sched/core.c:6804 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6819
schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common kernel/sched/completion.c:116 [inline]
wait_for_common kernel/sched/completion.c:127 [inline]
wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
__flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617
rxrpc_release_sock net/rxrpc/af_rxrpc.c:949 [inline]
rxrpc_release+0x258/0x420 net/rxrpc/af_rxrpc.c:979
__sock_release net/socket.c:659 [inline]
sock_release+0x82/0x150 net/socket.c:687
afs_open_socket+0x491/0x610 fs/afs/rxrpc.c:99
afs_net_init+0x7b9/0x9a0 fs/afs/main.c:124
ops_init+0x352/0x610 net/core/net_namespace.c:136
setup_net+0x4d1/0xbc0 net/core/net_namespace.c:339
copy_net_ns+0x4e4/0x7b0 net/core/net_namespace.c:495
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x619/0xc10 kernel/fork.c:3450
__do_sys_unshare kernel/fork.c:3521 [inline]
__se_sys_unshare kernel/fork.c:3519 [inline]
__x64_sys_unshare+0x38/0x40 kernel/fork.c:3519
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f3c7827dda9
RSP: 002b:00007f3c790080c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f3c783ac120 RCX: 00007f3c7827dda9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f3c782ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f3c783ac120 R15: 00007ffc8098eb48
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
4 locks held by kworker/u4:6/2512:
2 locks held by kworker/u4:7/2829:
#0: ffff888014c89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#0: ffff888014c89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#1: ffffc9000a8ffd20 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#1: ffffc9000a8ffd20 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
2 locks held by getty/4833:
#0: ffff88802a4820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
3 locks held by kworker/u4:10/14171:
#0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#1: ffffc9001350fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#1: ffffc9001350fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#2: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf5/0xb90 net/core/net_namespace.c:580
3 locks held by kworker/u5:1/16851:
#0: ffff88802057e948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#0: ffff88802057e948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#1: ffffc90004e9fd20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#1: ffffc90004e9fd20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#2: ffff88803e33d060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:305
4 locks held by syz-executor.3/18130:
1 lock held by syz-executor.0/20178:
#0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
1 lock held by syz-executor.2/20253:
#0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
1 lock held by syz-executor.1/20560:
#0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
4 locks held by kworker/u5:2/20818:
#0: ffff888015337148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#0: ffff888015337148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#1: ffffc9000c79fd20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
#1: ffffc9000c79fd20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
#2: ffff8880324e9060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:305
#3: ffff8880324e8078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xde0 net/bluetooth/hci_sync.c:5342
1 lock held by syz-executor.2/21152:
#0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491
1 lock held by syz-executor.4/21357:
#0: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939
2 locks held by syz-executor.2/21359:
#0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6612
#1: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939
1 lock held by syz-executor.3/21396:
#0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x706/0x1340 net/core/dev_ioctl.c:786
1 lock held by syz-executor.1/21401:
#0: ffff8880b943c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xfb0/0xff0 kernel/hung_task.c:379
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 21403 Comm: syz-executor.1 Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:mark_lock+0x120/0x350 kernel/locking/lockdep.c:4656
Code: 00 83 3d 22 07 14 0e 00 75 19 90 48 c7 c7 00 b5 aa 8b 48 c7 c6 a0 b7 aa 8b e8 dc c1 e5 ff 90 0f 0b 90 90 90 31 db 48 83 c3 60 <48> 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 8a e1 84 00
RSP: 0018:ffffc900031df7a8 EFLAGS: 00000086
RAX: 0000000000015180 RBX: ffffffff9299e500 RCX: ffffffff8171e2ea
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff92ca3450
RBP: 0000000000000003 R08: ffffffff92ca3457 R09: 1ffffffff259468a
R10: dffffc0000000000 R11: fffffbfff259468b R12: 0000000000000001
R13: dffffc0000000000 R14: 0000000000000008 R15: ffff88801a3828d8
FS: 00007f5a5824e6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f522000 CR3: 0000000080d10000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
mark_usage kernel/locking/lockdep.c:4579 [inline]
__lock_acquire+0x10e1/0x1fd0 kernel/locking/lockdep.c:5091
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__might_fault+0xc6/0x120 mm/memory.c:6063
do_recvmmsg+0x5e1/0xae0 net/socket.c:2945
__sys_recvmmsg net/socket.c:3018 [inline]
__do_sys_recvmmsg net/socket.c:3041 [inline]
__se_sys_recvmmsg net/socket.c:3034 [inline]
__x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f5a5747dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5a5824e0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f5a575ac050 RCX: 00007f5a5747dda9
RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007f5a574ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f5a575ac050 R15: 00007fff73b6d8b8
</TASK>


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[syzbot]

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