From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A78D3B3C18; Wed, 30 Sep 2026 19:20:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796013; cv=none; b=kADw+6MxzOXNoSC7g3fNY9/6k1/ULA5ERFIINBD2qt7gLUEe+uuVHQ8mrmQ8JM8ZkXzDRSOYe7x0imPCzvJLWD/gPWFUI8KVX1tPIuM8dEIV6SH7aCMbyrkaUrcLLaCg1owQIf4BnU/TJvC0OpYhyNOY2/snvtvIB1jKp7+cgFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796013; c=relaxed/simple; bh=0fKN/u5VBpXZZmiVBvxkoCPElA4SlOJ63F3n1ecQuVY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Mm2lefMHqA56kGRsR70iGeO7O+I/EkG500KcygH6gL5VFTH1TbMthvrDcnCusNA4Vs9slZNAi/DHjhb2DUhv20ebdJ8Er+KKzU6eib5PUhu9H9ggTrSBz4RqvY7RY3N+Mt6NQJ7NDfhuLthlCczwPBHZ2YseAfIgiogJeOYqLBM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=s53tgFOH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="s53tgFOH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C756D1F000FF; Wed, 30 Sep 2026 19:20:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796012; bh=LpNYISQiNHs0JOWzwfKDc1UKg3lTU+awY+ig5oFUdqw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=s53tgFOHI2yoNmF0VE8BZERimgZgf7uclE0+mZtMhvXuyo1jQBNxQUiPgB/qYO8Qd MjED6wpUHukqJZRAbMQ6NI7Iv5YmkVWc8dlFlUNxGTGNgpMA1SyMyz0blrd7a0djx1 QmoTASEHfzUnJqFY2SllcsVRhoXl7fSZlR3Y2Lm4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shardul Bankar , Xinyang Ge , Paolo Abeni , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 6.6 0708/1193] mptcp: close race between scheduler and state change Date: Wed, 30 Sep 2026 17:23:12 +0200 Message-ID: <20260930152449.980107819@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit 42064de57fb83231fcc89663a94885f228a1ee53 upstream. The mptcp scheduler may race with subflow sockets state change: data transmission on the selected socket may fail and a later release could try to use mss_now reset to 0 for a divide operation. Address the issue by explicitly checking for the critical scenario. Fixes: c886d70286bf ("mptcp: do not queue data on closed subflows") Cc: stable@vger.kernel.org Reported-by: Shardul Bankar Reported-by: Xinyang Ge Closes: https://lore.kernel.org/20260525194828.1137119-1-shardul.b@mpiricsoftware.com Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260917-net-mptcp-misc-fixes-7-3-rc4-v2-2-0cf5c72667c8@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1562,7 +1562,9 @@ struct sock *mptcp_subflow_get_send(stru static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info) { - tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal); + if (info->mss_now) + tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, + info->size_goal); release_sock(ssk); }