]> www.infradead.org Git - users/dwmw2/linux.git/commit
bpf: fix recursive lock when verdict program return SK_PASS
authorJiayuan Chen <mrpre@163.com>
Mon, 18 Nov 2024 03:09:09 +0000 (11:09 +0800)
committerJakub Kicinski <kuba@kernel.org>
Tue, 19 Nov 2024 03:39:59 +0000 (19:39 -0800)
commit8ca2a1eeadf09862190b2810697702d803ceef2d
tree78f1864768407dcf6fadba237f05922b9493a1be
parent21742be898fb6d99d4d85e293bd501b6870b503a
bpf: fix recursive lock when verdict program return SK_PASS

When the stream_verdict program returns SK_PASS, it places the received skb
into its own receive queue, but a recursive lock eventually occurs, leading
to an operating system deadlock. This issue has been present since v6.9.

'''
sk_psock_strp_data_ready
    write_lock_bh(&sk->sk_callback_lock)
    strp_data_ready
      strp_read_sock
        read_sock -> tcp_read_sock
          strp_recv
            cb.rcv_msg -> sk_psock_strp_read
              # now stream_verdict return SK_PASS without peer sock assign
              __SK_PASS = sk_psock_map_verd(SK_PASS, NULL)
              sk_psock_verdict_apply
                sk_psock_skb_ingress_self
                  sk_psock_skb_ingress_enqueue
                    sk_psock_data_ready
                      read_lock_bh(&sk->sk_callback_lock) <= dead lock

'''

This topic has been discussed before, but it has not been fixed.
Previous discussion:
https://lore.kernel.org/all/6684a5864ec86_403d20898@john.notmuch

Fixes: 6648e613226e ("bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue")
Reported-by: Vincent Whitchurch <vincent.whitchurch@datadoghq.com>
Signed-off-by: Jiayuan Chen <mrpre@163.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20241118030910.36230-2-mrpre@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/core/skmsg.c