From: Matthieu Baerts <matttbe@kernel.org>
To: Li Xiasong <lixiasong1@huawei.com>,
martineau@kernel.org, geliang@kernel.org, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
horms@kernel.org
Cc: netdev@vger.kernel.org, mptcp@lists.linux.dev,
linux-kernel@vger.kernel.org, weiyongjun1@huawei.com,
yuehaibing@huawei.com, zhangchangzhong@huawei.com
Subject: Re: [PATCH net] mptcp: fix soft lockup in mptcp_recvmsg()
Date: Tue, 3 Mar 2026 12:08:49 +0100 [thread overview]
Message-ID: <2fc4d789-5ee4-4618-8cb7-06a560d8c659@kernel.org> (raw)
In-Reply-To: <20260302052651.1466983-1-lixiasong1@huawei.com>
Hi Li,
On 02/03/2026 06:26, Li Xiasong wrote:
> syzbot reported a soft lockup in mptcp_recvmsg() [0].
>
> When receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not
> removed from the sk_receive_queue. This causes sk_wait_data() to always
> find available data and never perform actual waiting, leading to a soft
> lockup.
>
> Fix this by adding a 'last' parameter to track the last peeked skb.
> This allows sk_wait_data() to make informed waiting decisions and prevent
> infinite loops when MSG_PEEK is used.
Thank you for the patch! I will check why sk_wait_data() was not used
with the last SKB before.
By chance, do you have a reproducer that you could eventually share please?
Cheers,
Matt
--
Sponsored by the NGI0 Core fund.
next prev parent reply other threads:[~2026-03-03 11:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-02 5:26 [PATCH net] mptcp: fix soft lockup in mptcp_recvmsg() Li Xiasong
2026-03-03 11:08 ` Matthieu Baerts [this message]
2026-03-03 18:06 ` Matthieu Baerts
2026-03-04 9:24 ` Li Xiasong
2026-03-23 11:19 ` Matthieu Baerts
2026-03-04 9:07 ` Paolo Abeni
2026-03-04 11:33 ` Li Xiasong
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