Re: [PATCH net,v4] tcp: make sure init the accept_queue's spinlocks once

[Chen-Yu Tsai <wenst@chromium.org>]

On Mon, Jan 22, 2024 at 6:07 PM shaozhengchao <shaozhengchao@huawei.com> wrote:
>
> Hi Chen-Yu：
>          Thank you for your report. I had the same problem this morning.
> It has been verified locally.

I have a patch ready that I'll send out shortly.

ChenYu

> Zhengchao Shao
>
> On 2024/1/22 17:42, Chen-Yu Tsai wrote:
> > Hi,
> >
> > On Thu, Jan 18, 2024 at 09:20:19AM +0800, Zhengchao Shao wrote:
> >> When I run syz's reproduction C program locally, it causes the following
> >> issue:
> >> pvqspinlock: lock 0xffff9d181cd5c660 has corrupted value 0x0!
> >> WARNING: CPU: 19 PID: 21160 at __pv_queued_spin_unlock_slowpath (kernel/locking/qspinlock_paravirt.h:508)
> >> Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
> >> RIP: 0010:__pv_queued_spin_unlock_slowpath (kernel/locking/qspinlock_paravirt.h:508)
> >> Code: 73 56 3a ff 90 c3 cc cc cc cc 8b 05 bb 1f 48 01 85 c0 74 05 c3 cc cc cc cc 8b 17 48 89 fe 48 c7 c7
> >> 30 20 ce 8f e8 ad 56 42 ff <0f> 0b c3 cc cc cc cc 0f 0b 0f 1f 40 00 90 90 90 90 90 90 90 90 90
> >> RSP: 0018:ffffa8d200604cb8 EFLAGS: 00010282
> >> RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff9d1ef60e0908
> >> RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9d1ef60e0900
> >> RBP: ffff9d181cd5c280 R08: 0000000000000000 R09: 00000000ffff7fff
> >> R10: ffffa8d200604b68 R11: ffffffff907dcdc8 R12: 0000000000000000
> >> R13: ffff9d181cd5c660 R14: ffff9d1813a3f330 R15: 0000000000001000
> >> FS:  00007fa110184640(0000) GS:ffff9d1ef60c0000(0000) knlGS:0000000000000000
> >> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >> CR2: 0000000020000000 CR3: 000000011f65e000 CR4: 00000000000006f0
> >> Call Trace:
> >> <IRQ>
> >>    _raw_spin_unlock (kernel/locking/spinlock.c:186)
> >>    inet_csk_reqsk_queue_add (net/ipv4/inet_connection_sock.c:1321)
> >>    inet_csk_complete_hashdance (net/ipv4/inet_connection_sock.c:1358)
> >>    tcp_check_req (net/ipv4/tcp_minisocks.c:868)
> >>    tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2260)
> >>    ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205)
> >>    ip_local_deliver_finish (net/ipv4/ip_input.c:234)
> >>    __netif_receive_skb_one_core (net/core/dev.c:5529)
> >>    process_backlog (./include/linux/rcupdate.h:779)
> >>    __napi_poll (net/core/dev.c:6533)
> >>    net_rx_action (net/core/dev.c:6604)
> >>    __do_softirq (./arch/x86/include/asm/jump_label.h:27)
> >>    do_softirq (kernel/softirq.c:454 kernel/softirq.c:441)
> >> </IRQ>
> >> <TASK>
> >>    __local_bh_enable_ip (kernel/softirq.c:381)
> >>    __dev_queue_xmit (net/core/dev.c:4374)
> >>    ip_finish_output2 (./include/net/neighbour.h:540 net/ipv4/ip_output.c:235)
> >>    __ip_queue_xmit (net/ipv4/ip_output.c:535)
> >>    __tcp_transmit_skb (net/ipv4/tcp_output.c:1462)
> >>    tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6469)
> >>    tcp_rcv_state_process (net/ipv4/tcp_input.c:6657)
> >>    tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1929)
> >>    __release_sock (./include/net/sock.h:1121 net/core/sock.c:2968)
> >>    release_sock (net/core/sock.c:3536)
> >>    inet_wait_for_connect (net/ipv4/af_inet.c:609)
> >>    __inet_stream_connect (net/ipv4/af_inet.c:702)
> >>    inet_stream_connect (net/ipv4/af_inet.c:748)
> >>    __sys_connect (./include/linux/file.h:45 net/socket.c:2064)
> >>    __x64_sys_connect (net/socket.c:2073 net/socket.c:2070 net/socket.c:2070)
> >>    do_syscall_64 (arch/x86/entry/common.c:51 arch/x86/entry/common.c:82)
> >>    entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
> >>    RIP: 0033:0x7fa10ff05a3d
> >>    Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 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 8b 0d ab a3 0e 00 f7 d8 64 89 01 48
> >>    RSP: 002b:00007fa110183de8 EFLAGS: 00000202 ORIG_RAX: 000000000000002a
> >>    RAX: ffffffffffffffda RBX: 0000000020000054 RCX: 00007fa10ff05a3d
> >>    RDX: 000000000000001c RSI: 0000000020000040 RDI: 0000000000000003
> >>    RBP: 00007fa110183e20 R08: 0000000000000000 R09: 0000000000000000
> >>    R10: 0000000000000000 R11: 0000000000000202 R12: 00007fa110184640
> >>    R13: 0000000000000000 R14: 00007fa10fe8b060 R15: 00007fff73e23b20
> >> </TASK>
> >>
> >> The issue triggering process is analyzed as follows:
> >> Thread A                                       Thread B
> >> tcp_v4_rcv   //receive ack TCP packet       inet_shutdown
> >>    tcp_check_req                                  tcp_disconnect //disconnect sock
> >>    ...                                              tcp_set_state(sk, TCP_CLOSE)
> >>      inet_csk_complete_hashdance                ...
> >>        inet_csk_reqsk_queue_add                 inet_listen  //start listen
> >>          spin_lock(&queue->rskq_lock)             inet_csk_listen_start
> >>          ...                                        reqsk_queue_alloc
> >>          ...                                          spin_lock_init
> >>          spin_unlock(&queue->rskq_lock)      //warning
> >>
> >> When the socket receives the ACK packet during the three-way handshake,
> >> it will hold spinlock. And then the user actively shutdowns the socket
> >> and listens to the socket immediately, the spinlock will be initialized.
> >> When the socket is going to release the spinlock, a warning is generated.
> >> Also the same issue to fastopenq.lock.
> >>
> >> Move init spinlock to inet_create and inet_accept to make sure init the
> >> accept_queue's spinlocks once.
> >>
> >> Fixes: fff1f3001cc5 ("tcp: add a spinlock to protect struct request_sock_queue")
> >> Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path")
> >> Reported-by: Ming Shu <sming56@aliyun.com>
> >> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
> >
> > This patch causes a lockdep error for me on next-20240122 when SSHing
> > into my test device over IPv6. Reverting this patch gets rid of the
> > message, but that is probably not the correct fix.
> >
> > Given that inet_listen is also used from net/ipv6/af_inet6.c, and
> > __inet_listen_sk is used from mptcp, inet_init_csk_locks() would need
> > to be called in a couple more places. I don't know much about the
> > networking stack, but I can try to come up with a patch.
> >
> > Backtrace below:
> >
> > INFO: trying to register non-static key.
> > The code is fine but needs lockdep annotation, or maybe
> > you didn't initialize this object before use?
> > turning off the locking correctness validator.
> > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.8.0-rc1-next-20240122-01036-g319fbd8fc6d3 #147 2400bce4623c16f3873f828b5d429524a0849cd3
> > Hardware name: Google Krane Chromebook (DT)
> > Call trace:
> > dump_backtrace (arch/arm64/kernel/stacktrace.c:293)
> > show_stack (arch/arm64/kernel/stacktrace.c:300)
> > dump_stack_lvl (lib/dump_stack.c:107)
> > dump_stack (lib/dump_stack.c:114)
> > register_lock_class (kernel/locking/lockdep.c:977 kernel/locking/lockdep.c:1289)
> > __lock_acquire (kernel/locking/lockdep.c:5014)
> > lock_acquire (./arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756 kernel/locking/lockdep.c:5719)
> > _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154)
> > inet_csk_complete_hashdance (net/ipv4/inet_connection_sock.c:1303 net/ipv4/inet_connection_sock.c:1355)
> > tcp_check_req (net/ipv4/tcp_minisocks.c:653)
> > tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1837)
> > ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:438)
> > ip6_input_finish (./include/linux/rcupdate.h:779 net/ipv6/ip6_input.c:484)
> > ip6_input (./include/linux/netfilter.h:314 ./include/linux/netfilter.h:308 net/ipv6/ip6_input.c:492)
> > ip6_sublist_rcv_finish (net/ipv6/ip6_input.c:86 (discriminator 3))
> > ip6_sublist_rcv (net/ipv6/ip6_input.c:317)
> > ipv6_list_rcv (net/ipv6/ip6_input.c:326)
> > __netif_receive_skb_list_core (net/core/dev.c:5577 net/core/dev.c:5625)
> > netif_receive_skb_list_internal (net/core/dev.c:5679 net/core/dev.c:5768)
> > napi_complete_done (./include/linux/list.h:37 (discriminator 2) ./include/net/gro.h:440 (discriminator 2) ./include/net/gro.h:435 (discriminator 2) net/core/dev.c:6108 (discriminator 2))
> > r8152_poll (drivers/net/usb/r8152.c:2780 (discriminator 1)) r8152
> > __napi_poll.constprop.0 (net/core/dev.c:6576)
> > net_rx_action (net/core/dev.c:6647 net/core/dev.c:6778)
> > __do_softirq (./arch/arm64/include/asm/jump_label.h:21 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
> > ____do_softirq (arch/arm64/kernel/irq.c:82)
> > call_on_irq_stack (arch/arm64/kernel/entry.S:895)
> > do_softirq_own_stack (arch/arm64/kernel/irq.c:87)
> > __irq_exit_rcu (./arch/arm64/include/asm/percpu.h:44 kernel/softirq.c:612 kernel/softirq.c:634)
> > irq_exit_rcu (kernel/softirq.c:646 (discriminator 4))
> > el1_interrupt (arch/arm64/kernel/entry-common.c:505 arch/arm64/kernel/entry-common.c:517)
> > el1h_64_irq_handler (arch/arm64/kernel/entry-common.c:523)
> > el1h_64_irq (arch/arm64/kernel/entry.S:594)
> > arch_local_irq_enable (./arch/arm64/include/asm/irqflags.h:51)
> > cpuidle_enter (drivers/cpuidle/cpuidle.c:388)
> > do_idle (kernel/sched/idle.c:134 kernel/sched/idle.c:215 kernel/sched/idle.c:312)
> > cpu_startup_entry (kernel/sched/idle.c:409)
> > rest_init (./include/linux/rcupdate.h:751 (discriminator 1) init/main.c:701 (discriminator 1))
> > arch_call_rest_init+0x1c/0x28
> > start_kernel (init/main.c:1023 (discriminator 1))
> > __primary_switched (arch/arm64/kernel/head.S:524)
> >
> >
> > Regards
> > ChenYu
> >
> >> ---
> >> v4: Add a helper to init accept_queue's spinlocks.
> >> v3: Move init spinlock to inet_create and inet_accept.
> >> v2: Add 'init_done' to make sure init the accept_queue's spinlocks once.
> >> ---
> >>   include/net/inet_connection_sock.h | 8 ++++++++
> >>   net/core/request_sock.c            | 3 ---
> >>   net/ipv4/af_inet.c                 | 3 +++
> >>   net/ipv4/inet_connection_sock.c    | 4 ++++
> >>   4 files changed, 15 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
> >> index d0a2f827d5f2..9ab4bf704e86 100644
> >> --- a/include/net/inet_connection_sock.h
> >> +++ b/include/net/inet_connection_sock.h
> >> @@ -357,4 +357,12 @@ static inline bool inet_csk_has_ulp(const struct sock *sk)
> >>      return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops;
> >>   }
> >>
> >> +static inline void inet_init_csk_locks(struct sock *sk)
> >> +{
> >> +    struct inet_connection_sock *icsk = inet_csk(sk);
> >> +
> >> +    spin_lock_init(&icsk->icsk_accept_queue.rskq_lock);
> >> +    spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock);
> >> +}
> >> +
> >>   #endif /* _INET_CONNECTION_SOCK_H */
> >> diff --git a/net/core/request_sock.c b/net/core/request_sock.c
> >> index f35c2e998406..63de5c635842 100644
> >> --- a/net/core/request_sock.c
> >> +++ b/net/core/request_sock.c
> >> @@ -33,9 +33,6 @@
> >>
> >>   void reqsk_queue_alloc(struct request_sock_queue *queue)
> >>   {
> >> -    spin_lock_init(&queue->rskq_lock);
> >> -
> >> -    spin_lock_init(&queue->fastopenq.lock);
> >>      queue->fastopenq.rskq_rst_head = NULL;
> >>      queue->fastopenq.rskq_rst_tail = NULL;
> >>      queue->fastopenq.qlen = 0;
> >> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> >> index 835f4f9d98d2..4e635dd3d3c8 100644
> >> --- a/net/ipv4/af_inet.c
> >> +++ b/net/ipv4/af_inet.c
> >> @@ -330,6 +330,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
> >>      if (INET_PROTOSW_REUSE & answer_flags)
> >>              sk->sk_reuse = SK_CAN_REUSE;
> >>
> >> +    if (INET_PROTOSW_ICSK & answer_flags)
> >> +            inet_init_csk_locks(sk);
> >> +
> >>      inet = inet_sk(sk);
> >>      inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
> >>
> >> diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
> >> index 8e2eb1793685..459af1f89739 100644
> >> --- a/net/ipv4/inet_connection_sock.c
> >> +++ b/net/ipv4/inet_connection_sock.c
> >> @@ -727,6 +727,10 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
> >>      }
> >>      if (req)
> >>              reqsk_put(req);
> >> +
> >> +    if (newsk)
> >> +            inet_init_csk_locks(newsk);
> >> +
> >>      return newsk;
> >>   out_err:
> >>      newsk = NULL;
> >> --
> >> 2.34.1
> >>