From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 94559283FCF; Mon, 4 May 2026 09:51:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777888319; cv=none; b=SvJKTNYsf3Glv4j271TBL3YSf120mlN6PLDC6qw266mbcVB+Z+Jzg1FrnUAdGpahBJjn+apN6yqwaTqDOeA9FM2DMmLamS5ropae4ngIjNmOjW3dqkLVVUMiQ6ynhmsVIXzNQSwt91jrisN6s++HMUzdfCZT5qf3MR1VkTIk06w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777888319; c=relaxed/simple; bh=S5cf9/E9C4bvHrpvqQ7Fnx33EqDMw0al7kzY6fuZAf4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xi297bNM8nYFTyDQViEtUyJvk2B0r2ftdEsoNErxbQ+IgTywKE9Uw9Uc8T7z9lYXX2tIig1EJ/lpYcDVht+2NX9aBb0RXytf7FAPrDuIKWN/2xrDQ7IkxSweZ9/nMki7J6ErAtbHGE1dEFNQYvTsHsMKNOkIcxmQ641VwxWVb6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HlGv4TUo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HlGv4TUo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E86F2C2BCB9; Mon, 4 May 2026 09:51:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777888319; bh=S5cf9/E9C4bvHrpvqQ7Fnx33EqDMw0al7kzY6fuZAf4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HlGv4TUohlBqRjXFj9boGXxPWlXHTJRV4W9S5uSGiyHqlt6sC9Z0/9GZ1AtOcFYKf T9XRIYHOFCYYaxX0CcdkxhEU5egSJsgI81xSXbE25jLVSXgTAAKmOQyVV/qpe7qAWi KMCNm1mLvW3rYPIArAU4kI9ilHQnU3jG+ZoxvFI7bf+c3te5Lwgbiqsk71D/fbRXGn owh4YX3LkCctbIjRMWmVq2mPIR0rqvdPOxLw6FqplZJoIEnEG9wjWUKCt6WPz5OuIL Hi8cxpCS7WVBB5LtP8MmxVk9wuxLXFTs+cRZRXk3uctq76xbjwj7BEaP7TKEs97giB FvH+yyHOLbxuQ== From: "Matthieu Baerts (NGI0)" To: mptcp@lists.linux.dev Cc: "Matthieu Baerts (NGI0)" , syzbot+ff020673c5e3d94d9478@syzkaller.appspotmail.com, Paolo Abeni , Kuniyuki Iwashima , syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org Subject: [PATCH] mptcp: fix KMSAN: uninit-value in mptcp_established_options Date: Mon, 4 May 2026 11:51:02 +0200 Message-ID: <20260504095101.852039-2-matttbe@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <69f44505.050a0220.3cbe47.0008.GAE@google.com> References: <69f44505.050a0220.3cbe47.0008.GAE@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1098; i=matttbe@kernel.org; h=from:subject; bh=S5cf9/E9C4bvHrpvqQ7Fnx33EqDMw0al7kzY6fuZAf4=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGDJ/5LD9f/Jf6Wsjj9m7Fk3jQznvSvTObryyhCEx+j3rL J64DPuqjlIWBjEuBlkxRRbptsj8mc+reEu8/Cxg5rAygQxh4OIUgImcCGdkODOj5b+pxy2NQxW6 fN6SM+wKGKbHnu9ymfT/Xu3cL/+rUxn+6QvH+aezxixWlc8IF7nN86bveYRi893uhZf1jx9bpqP CBAA= X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 Content-Transfer-Encoding: 8bit Just to let syzbot testing it. See Paolo's suggestion from [1]. Link: https://lore.kernel.org/6d342ef2-d480-4be6-afad-a3841cf205a8@redhat.com [1] Fixes: cfcceb7a39fc ("tcp: shrink per-packet memset in __tcp_transmit_skb()") Reported-by: syzbot+ff020673c5e3d94d9478@syzkaller.appspotmail.com Closes: https://lore.kernel.org/69f44505.050a0220.3cbe47.0008.GAE@google.com Suggested-by: Paolo Abeni Signed-off-by: Matthieu Baerts (NGI0) --- Cc: Kuniyuki Iwashima Cc: syzkaller-bugs@googlegroups.com Cc: linux-kernel@vger.kernel.org --- net/mptcp/options.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 8a1c5698983c..24903a12a4e0 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -583,6 +583,8 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, map_size += TCPOLEN_MPTCP_DSS_CHECKSUM; opts->ext_copy = *mpext; + } else { + opts->ext_copy.use_map = 0; } dss_size = map_size; -- 2.53.0