From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: <netdev-bot+sashiko@kernel.org>
Cc: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>,
<daniel@iogearbox.net>, <andrii@kernel.org>, <eddyz87@gmail.com>,
<memxor@gmail.com>, <john.fastabend@gmail.com>,
<jakub@cloudflare.com>, <jiayuan.chen@linux.dev>,
<davem@davemloft.net>, <edumazet@kernel.org>, <kuba@kernel.org>,
<pabeni@redhat.com>, <horms@kernel.org>, <kuniyu@google.com>,
<willemb@google.com>, <matttbe@kernel.org>,
<mptcp@lists.linux.dev>, <mason@kernel.org>,
<josef@toxicpanda.com>
Subject: Re: [PATCH bpf v2 07/15] bpf, sockmap: Check the target of an egress redirect before each send
Date: Wed, 04 Nov 2026 00:29:33 +0000 [thread overview]
Message-ID: <DMM02SF04UK0.3RQNDSDPR2SGW@gmail.com> (raw)
In-Reply-To: <179374188061.488855.10389706003415159913@kernel.org>
On Tue, Nov 03, 2026 at 01:38 PM netdev-bot+sashiko@kernel.org <netdev-bot+sashiko@kernel.org> wrote:
> This isn't a bug introduced by this patch, but the comment mentions
> unaccepted children as redirect targets. Can tcp_bpf_push_locked() hold
> the lock of such a child while the listener tears it down?
yeah. It's an old bug, not from this patch, and not only in sockmap.
inet_csk_listen_stop() takes only the BH lock of the child.
tcp_abort() calls lock_sock() on such a child too. See
commit dbd62ad55a4c ("tcp: avoid double destroy in tcp_abort() of an
unaccepted child").
> After that, the retry check here returns -EPIPE. So the window exists only
> at this commit, or in a backport that takes this patch without the next
> one.
>
> Could the series be reordered so that fix lands first?
No need. The window is there without this patch too.
This patch doesn't add it, and patch 8 closes it.
Both patches have Fixes: 4f738adba30a.
> This is a pre-existing issue, but it is related to the sleep above. Is a
> redirect sender that sleeps in sk_stream_wait_memory() on the target woken
> at all when the target's owner closes it?
It isn't. It's an old bug, not from this patch.
The sleep is interruptible. A signal or SO_SNDTIMEO of the target ends it.
next prev parent reply other threads:[~2026-11-04 0:29 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-02 7:20 [PATCH bpf v2 00/15] bpf, sockmap: Fixes for verdicts, redirects, corks and recvmsg() Alexei Starovoitov
2026-11-02 7:20 ` [PATCH bpf v2 01/15] bpf, sockmap: Write sg.start when recvmsg() faults Alexei Starovoitov
2026-11-02 8:32 ` Jiayuan Chen
2026-11-02 7:20 ` [PATCH bpf v2 02/15] bpf, sockmap: Don't let an SK_DROP verdict stick Alexei Starovoitov
2026-11-02 8:45 ` Jiayuan Chen
2026-11-02 18:47 ` John Fastabend
2026-11-02 7:21 ` [PATCH bpf v2 03/15] bpf, sockmap: Don't let an SK_PASS verdict cover the next message Alexei Starovoitov
2026-11-02 18:51 ` John Fastabend
2026-11-02 22:44 ` Alexei Starovoitov
2026-11-03 21:37 ` netdev-bot+sashiko
2026-11-04 0:28 ` Alexei Starovoitov
2026-11-04 1:32 ` Jiayuan Chen
2026-11-04 2:04 ` Alexei Starovoitov
2026-11-02 7:21 ` [PATCH bpf v2 04/15] bpf, sockmap: Subtract all dropped bytes from the return value Alexei Starovoitov
2026-11-02 11:19 ` Jiayuan Chen
2026-11-02 19:12 ` John Fastabend
2026-11-02 7:21 ` [PATCH bpf v2 05/15] bpf, sockmap: Clear the resume state of a stopped psock Alexei Starovoitov
2026-11-02 11:40 ` Jiayuan Chen
2026-11-02 19:16 ` John Fastabend
2026-11-02 7:21 ` [PATCH bpf v2 06/15] bpf, sockmap: Give no progs to a TCP listener Alexei Starovoitov
2026-11-02 12:00 ` Jiayuan Chen
2026-11-02 19:31 ` John Fastabend
2026-11-03 21:37 ` netdev-bot+sashiko
2026-11-04 0:29 ` Alexei Starovoitov
2026-11-02 7:21 ` [PATCH bpf v2 07/15] bpf, sockmap: Check the target of an egress redirect before each send Alexei Starovoitov
2026-11-02 12:32 ` Jiayuan Chen
2026-11-02 16:18 ` Alexei Starovoitov
2026-11-02 19:36 ` John Fastabend
2026-11-03 21:38 ` netdev-bot+sashiko
2026-11-04 0:29 ` Alexei Starovoitov [this message]
2026-11-02 7:21 ` [PATCH bpf v2 08/15] net: Leave sk_stream_wait_memory() once the socket is dead Alexei Starovoitov
2026-11-02 12:54 ` Jiayuan Chen
2026-11-04 5:23 ` Eric Dumazet
2026-11-02 7:21 ` [PATCH bpf v2 09/15] bpf, sockmap: Check the TCP state in recvmsg() Alexei Starovoitov
2026-11-02 15:15 ` Jiayuan Chen
2026-11-02 16:57 ` Matthieu Baerts
2026-11-03 21:38 ` netdev-bot+sashiko
2026-11-04 0:29 ` Alexei Starovoitov
2026-11-02 7:21 ` [PATCH bpf v2 10/15] bpf, sockmap: Reset the copy position when corking Alexei Starovoitov
2026-11-03 1:39 ` Jiayuan Chen
2026-11-02 7:21 ` [PATCH bpf v2 11/15] bpf, sockmap: Don't copy 0 bytes into a full cork Alexei Starovoitov
2026-11-03 1:41 ` Jiayuan Chen
2026-11-02 7:21 ` [PATCH bpf v2 12/15] bpf, sockmap: Clear the redirect target before the sk_msg prog runs Alexei Starovoitov
2026-11-03 1:58 ` Jiayuan Chen
2026-11-02 7:21 ` [PATCH bpf v2 13/15] bpf, sockmap: Check that the redirected message is the cork Alexei Starovoitov
2026-11-03 2:07 ` Jiayuan Chen
2026-11-02 7:21 ` [PATCH bpf v2 14/15] bpf, sockmap: Keep the rest of the cork after a redirect Alexei Starovoitov
2026-11-03 2:25 ` Jiayuan Chen
2026-11-03 21:38 ` netdev-bot+sashiko
2026-11-04 0:30 ` Alexei Starovoitov
2026-11-02 7:21 ` [PATCH bpf v2 15/15] bpf, sockmap: Clear the end mark of elements added by push and pop Alexei Starovoitov
2026-11-03 2:51 ` Jiayuan Chen
2026-11-02 20:11 ` [PATCH bpf v2 00/15] bpf, sockmap: Fixes for verdicts, redirects, corks and recvmsg() John Fastabend
2026-11-04 5:24 ` Eric Dumazet
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