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 66FC5330D43; Sat, 19 Sep 2026 20:06:10 +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=1789848371; cv=none; b=A9aF3WF/+8aOmXHrVrdth0dBrfhRGWXhT30RcLbAzC9QaUqVV4ShH31aZkyxo3WEdEv6WPx9VZGkROSK7QMxQ+iB3P94HmQB7l9xneXehbaE+RLNNdEdAdGqEu1nphYNYn3XyhwjB9Wd8YIKt3x4x4oPbu21eRJaj1yT86CJous= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789848371; c=relaxed/simple; bh=e4GcvulTmIeF7pJbzhJ1erHzPXPReTT3p0D910LabfE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X3g3ozjTUSiPpmbBzcNsXydRQ5AzGYkyU5CIFfc1Tz6ta48yYzGCNstjlzMvO5O6c5rzQPV3GhQ3gqIq6D/XFny//AGpNPDAH6PLmCqjboKEk4ETU+8NhtYdxIeO0TAh2BfORkgkqPbY5pPkSpxJgBYNv3pszxgDxGJtlXC4jU4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YdbPHS1f; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YdbPHS1f" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB5E31F000FF; Sat, 19 Sep 2026 20:06:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789848370; bh=qEY2FJ8Rgril9UKqC5Rr28fJAVFEpeyKx/yCnNC5Ja8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YdbPHS1flSokBNDXjTKYNxNn2D/GkUYsyJxoDwrZw0CDDV/J/9ohVNpr5ENzlqkdT 0JRGUf++XQ/3HYCu4icj9IvIpZOOTSGJ3WEgAuczyCsupDsri/qwJY0wpJlSdYKVuz OfdR6ZDVKmIGqRZPURfczcRjISD4VqFWVs7Zq09GAxLmG/m2oi2U8IPYm9JcZ/eTHK qEGaMnm+HW2ld1H32Nb3NOZz24jko5kLpmPiBXCMh1Kp693kDUgUl4k/RNX3hgX0yP MPO17pcRsOO6PB9Dru6wRCFCHry1BgfqJ3c2zSU/m/FOQyJNBR3i8/kNayrBI3lD1L UFF7xWN5TQvwg== From: "Matthieu Baerts (NGI0)" To: mptcp@lists.linux.dev, stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: Paolo Abeni , sashal@kernel.org, Shardul Bankar , Xinyang Ge , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 6.6.y 2/3] mptcp: close race between scheduler and state change Date: Sat, 19 Sep 2026 22:05:57 +0200 Message-ID: <20260919200554.2005069-7-matttbe@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260919200554.2005069-5-matttbe@kernel.org> References: <20260919200554.2005069-5-matttbe@kernel.org> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1636; i=matttbe@kernel.org; h=from:subject; bh=QLZQJZfmNd524Nka0ukf8EFcTGME13LrnpryXEQN+5Q=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGLLWvVbbxZ9zb3XxW2/ejK1O7fyi0T0qfkcXFO/49zz6+ DpNzlC5jlIWBjEuBlkxRRbptsj8mc+reEu8/Cxg5rAygQxh4OIUgImcFGb4Zxm+nOHnt4U2kQee L5xyS+fre83pPU0lflOXKX6QdvAVdmdk2JHtsrVz5T++RKeW5Dkd22tXfTA9s7NAV/Hjvhk2j1K c2AA= X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 Content-Transfer-Encoding: 8bit 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) --- net/mptcp/protocol.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 187e60ab3f77..3c1ad8601fb2 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1562,7 +1562,9 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) 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); } -- 2.55.0