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 20ED331E0FB; Mon, 18 Aug 2025 12:52:41 +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=1755521561; cv=none; b=KaD/QCdIajPIJ5kznELerbak+5iVGa8ZGzFc65VyQI0NnW73N3+KII3CP6leSr1f4rXuGmra9VI5ZXWjnqUprp+Twy1QyUioUPGWPnCDG92WXI1TDodI2PMKoHc44IrJ2rGY1myDO1dmyTOxxIx/3vNR3leJUjT/ipceKMUb8gQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755521561; c=relaxed/simple; bh=683vTj0DqQ7QLdL4a5RHXiGJeaPMRhLCirKSgOHvB+I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bIZrAcPzxJ9OH+TIyf1eH7YQF1ynLRqMoBf3k/kGCZzHxUdIMNdi4LmzLVoMW21NZzwL1plC+cOCItTO1niQ71jJlGMGK37Z3TmkkyJgSQiOormPRrmCjBKcDNd+igPQEPxBog+S1aaQ1b9I4Axem+orRA/M+p+tnQnAoGm1fZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ahx3F3hq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ahx3F3hq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8629DC4CEEB; Mon, 18 Aug 2025 12:52:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755521561; bh=683vTj0DqQ7QLdL4a5RHXiGJeaPMRhLCirKSgOHvB+I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ahx3F3hqvMpX+ctQhi29b3ucQsYAPPPfl4mItniI4u11pviho8oGqIb/CSXz5AeXQ 0j+qpZvAQOQQPNfZFygPKoZWJFJQJKHl5PnbbvKS4ek2cOtZOZ3zm4kJBzNyLwllNX UlMGxUoCwIOr0Do2WlbhakHXHRJKX33/yfud5cCM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+773e51afe420baaf0e2b@syzkaller.appspotmail.com, syzbot+70a42f45e76bede082be@syzkaller.appspotmail.com, Xin Long , Marcelo Ricardo Leitner , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 058/444] sctp: linearize cloned gso packets in sctp_rcv Date: Mon, 18 Aug 2025 14:41:24 +0200 Message-ID: <20250818124451.107975876@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250818124448.879659024@linuxfoundation.org> References: <20250818124448.879659024@linuxfoundation.org> User-Agent: quilt/0.68 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit fd60d8a086191fe33c2d719732d2482052fa6805 ] A cloned head skb still shares these frag skbs in fraglist with the original head skb. It's not safe to access these frag skbs. syzbot reported two use-of-uninitialized-memory bugs caused by this: BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122 __release_sock+0x1da/0x330 net/core/sock.c:3106 release_sock+0x6b/0x250 net/core/sock.c:3660 sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360 sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885 sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031 inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:718 [inline] and BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] This patch fixes it by linearizing cloned gso packets in sctp_rcv(). Fixes: 90017accff61 ("sctp: Add GSO support") Reported-by: syzbot+773e51afe420baaf0e2b@syzkaller.appspotmail.com Reported-by: syzbot+70a42f45e76bede082be@syzkaller.appspotmail.com Signed-off-by: Xin Long Reviewed-by: Marcelo Ricardo Leitner Link: https://patch.msgid.link/dd7dc337b99876d4132d0961f776913719f7d225.1754595611.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sctp/input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sctp/input.c b/net/sctp/input.c index a8a254a5008e..032a10d82302 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -117,7 +117,7 @@ int sctp_rcv(struct sk_buff *skb) * it's better to just linearize it otherwise crc computing * takes longer. */ - if ((!is_gso && skb_linearize(skb)) || + if (((!is_gso || skb_cloned(skb)) && skb_linearize(skb)) || !pskb_may_pull(skb, sizeof(struct sctphdr))) goto discard_it; -- 2.50.1