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 3B43737DEBE; Sat, 17 Oct 2026 16:21:02 +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=1792254063; cv=none; b=AmsWmPl96Sw8kwJVU9A6EfYhpdG+7bfTgDSkiD/XklHOvNOxyJtFklddCG7m2tFBl8bzhI5aJlgRLGWthQSvvuV0kyfIwp/pwZSSNFJARnasyoB7dEBsyrlVfFoAwY3Rmc3LE7Duh8falUng0sW7eKhDl1aI/YbDyh44fXx6hiE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792254063; c=relaxed/simple; bh=/vnRTCT5LruPoDX/2lQC1bPhW9uabHDPZypWF3OPvSw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IKVieC2X5jcz6YxPm3poRV9CHbkMw+PeWhu8jkBdRVhD/kgFfKUgr1cZt6Ur95+hWF44A+EBzQFg9t7cZuk9Ny3pXzz23Ksej2c22df8ysEj3tism1bGG5owYBzmmSL9Mhzi6yTnFcn45Kbb4q1a0jjV49GK9VP9m1BeCNETvGA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Mq1KbSAn; 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="Mq1KbSAn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 906B51F000C4; Sat, 17 Oct 2026 16:21:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792254062; bh=PxKD2vp2fMu9WrxAbgftEUhFNBmXymHROllJySRC/W4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Mq1KbSAncnQGuiV+Lq7VRQ+9Fmz55iMHi3h2Qo/javy/wqq6DJNha360eynJnNVQe aiB9C+JqZs49zqSBAKsOOermHtRxy2NrOVfSwsuWB7pT9k014hAxY2N2TIIwpB/KI8 ny4lRQ6vVcCBtYy7oFKbfelrvVBEebeOpUl1mQfI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Xin Long , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 322/869] sctp: validate embedded INIT chunk and address list lengths in cookie Date: Sat, 17 Oct 2026 17:52:43 +0200 Message-ID: <20261017160045.333294847@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160036.979869304@linuxfoundation.org> References: <20261017160036.979869304@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit 6f4c80a2a7e6d06753b89a578b710a2499a5e62b ] sctp_unpack_cookie() only checked that the embedded INIT chunk length did not exceed the remaining cookie payload, but did not ensure that the INIT chunk is large enough to contain a complete INIT header. A malformed COOKIE_ECHO can therefore carry a truncated INIT chunk whose length field is smaller than sizeof(struct sctp_init_chunk). Later, sctp_process_init() accesses INIT parameters unconditionally, which may lead to out-of-bounds reads. In addition, raw_addr_list_len is not fully validated against the remaining cookie payload. When cookie authentication is disabled, an attacker can supply an oversized raw_addr_list_len and cause sctp_raw_to_bind_addrs() to read beyond the end of the cookie. The address parser also lacks sufficient bounds checks for parameter headers and lengths, allowing malformed address parameters to trigger out-of-bounds reads. Fix this by: - requiring the embedded INIT chunk length to be at least sizeof(struct sctp_init_chunk); - validating that the INIT chunk and raw address list together fit within the cookie payload; - verifying sufficient data exists for each address parameter header and payload before parsing it. Note that sctp_verify_init() must be called after sctp_unpack_cookie() and before sctp_process_init() when cookie authentication is disabled. This will be addressed in a separate patch. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Sashiko Signed-off-by: Xin Long Link: https://patch.msgid.link/75af23a89adf881a0895d511775e4770da367cbf.1780873427.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sctp/bind_addr.c | 11 ++++++++++- net/sctp/sm_make_chunk.c | 12 +++++++++++- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c index 6b95d3ba8fe1c..0947b276d1e08 100644 --- a/net/sctp/bind_addr.c +++ b/net/sctp/bind_addr.c @@ -275,6 +275,16 @@ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, param = (struct sctp_paramhdr *)raw_addr_list; rawaddr = (union sctp_addr_param *)raw_addr_list; + if (addrs_len < sizeof(*param)) { + retval = -EINVAL; + goto out_err; + } + len = ntohs(param->length); + if (addrs_len < len) { + retval = -EINVAL; + goto out_err; + } + af = sctp_get_af_specific(param_type2af(param->type)); if (unlikely(!af) || !af->from_addr_param(&addr, rawaddr, htons(port), 0)) { @@ -291,7 +301,6 @@ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, goto out_err; next: - len = ntohs(param->length); addrs_len -= len; raw_addr_list += len; } diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 2366dd0298ebd..bec5bd6cf1d1f 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1750,8 +1750,9 @@ struct sctp_association *sctp_unpack_cookie( struct sk_buff *skb = chunk->skb; struct sctp_cookie *bear_cookie; __u8 *digest = ep->digest; + struct sctp_chunkhdr *ch; + unsigned int len, chlen; enum sctp_scope scope; - unsigned int len; ktime_t kt; /* Header size is static data prior to the actual cookie, including @@ -1779,6 +1780,15 @@ struct sctp_association *sctp_unpack_cookie( cookie = chunk->subh.cookie_hdr; bear_cookie = &cookie->c; + ch = (struct sctp_chunkhdr *)(bear_cookie + 1); + chlen = ntohs(ch->length); + if (chlen < sizeof(struct sctp_init_chunk)) + goto malformed; + if (chlen > len - fixed_size) + goto malformed; + if (bear_cookie->raw_addr_list_len > len - fixed_size - chlen) + goto malformed; + if (!sctp_sk(ep->base.sk)->hmac) goto no_hmac; -- 2.53.0