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 454343B42DC; Mon, 17 Aug 2026 14:26:45 +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=1786976806; cv=none; b=fDMkAuQ9X6YF5OohfRktJ//tEz4FBxYSyt3m5rVc8T9L7MvED5sfN1P2MvJ+pYRz2JQPgIRk5EY6Qr4d68iwkOiiHHpDr8S1qr70qy/764dZp3wgIy5Mz9ibJwab36SYP6ShbsveGQhv70MWqdfy4hqcy+DUVV2yEXNGmrxFnRs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786976806; c=relaxed/simple; bh=vLM0gMw+wUVRpBYwogLYURa3NdAiB8Zgp60myV1g5Jo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nV5+S9XmZbFdfOabhc3u7LjLxkS+sMVYszjP+edaE4fA8l0FLvgZeoheRG4/PCbxtahJMAnxFoXx4GTGkZvjRAW9hfOTN6x4dkDxbd19mPRCD6Dgr95C/a3gS8vKSziAN/nBBM5QJTs5urV1G+2Q0ksBzgou5bwywmucFIJ/bI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=coW+Pwah; 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="coW+Pwah" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F1131F000E9; Mon, 17 Aug 2026 14:26:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786976805; bh=81XM4rRWvPJG6qNP2EdT796eDHP87KsvcV9cKA+MsYs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=coW+Pwah0/ve2sVAb+lPgfIaJfI1cHIUAC4R7Dnlgk9T+j28/UdaPkji+aYs5OzJ5 j2LBU04XyPp9tXYJD/d7WRQm5swimPXr3ckrcN1pz94AIXBuXG7cnTfs+iRTfSM/K+ hQ7d1cixoR49HXBV2Zk5tbxMYY1Kb0E1s155PrOY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, AutonomousCodeSecurity@microsoft.com, Xin Long , "Cen Zhang (Microsoft)" , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 111/456] sctp: validate stream count in sctp_process_strreset_inreq() Date: Mon, 17 Aug 2026 15:28:21 +0200 Message-ID: <20260817132544.428790639@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cen Zhang (Microsoft) [ Upstream commit 18ae07691d43183d270de8be9dc8e027906015d9 ] When processing a RESET_IN_REQUEST from a peer, sctp_process_strreset_inreq() derives the stream count from the parameter length but does not check whether the resulting RESET_OUT_REQUEST would exceed SCTP_MAX_CHUNK_LEN. The OUT request header (sctp_strreset_outreq, 16 bytes) is 8 bytes larger than the IN request header (sctp_strreset_inreq, 8 bytes). Generally, the IP payload is bounded to 65535 bytes, so the stream list cannot be large enough to trigger the overflow. However, on interfaces with MTU > 65535 (e.g., loopback with IPv6 jumbograms), a stream list that fits within the incoming IN parameter can cause a __u16 overflow in sctp_make_strreset_req() when computing the OUT request size, leading to an undersized skb allocation and a kernel BUG: net/core/skbuff.c:207 skb_panic net/core/skbuff.c:2625 skb_put net/sctp/sm_make_chunk.c:1535 sctp_addto_chunk net/sctp/sm_make_chunk.c:3695 sctp_make_strreset_req net/sctp/stream.c:655 sctp_process_strreset_inreq The local setsockopt path validates the generated reset request size. However, for an incoming-only reset, it accounts for the smaller IN request even though the peer must generate an OUT request with the same stream list. Such a request cannot be completed successfully by the peer. Reject peer IN requests whose corresponding OUT request would exceed SCTP_MAX_CHUNK_LEN. Also tighten the local check so it does not send an IN request that would require an oversized OUT request from the peer. Fixes: 7f9d68ac944e ("sctp: implement sender-side procedures for SSN Reset Request Parameter") Reported-by: AutonomousCodeSecurity@microsoft.com Closes: https://lore.kernel.org/all/20260707203215.2752-1-blbllhy@gmail.com/ Suggested-by: Xin Long Signed-off-by: Cen Zhang (Microsoft) Acked-by: Xin Long Link: https://patch.msgid.link/20260710010718.20318-1-blbllhy@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sctp/stream.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/sctp/stream.c b/net/sctp/stream.c index d38e5431f359dc..34754ba23198ae 100644 --- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -308,7 +308,8 @@ int sctp_send_reset_streams(struct sctp_association *asoc, goto out; param_len += str_nums * sizeof(__u16) + - sizeof(struct sctp_strreset_inreq); + (out ? sizeof(struct sctp_strreset_inreq) + : sizeof(struct sctp_strreset_outreq)); } if (param_len > SCTP_MAX_CHUNK_LEN - @@ -639,6 +640,9 @@ struct sctp_chunk *sctp_process_strreset_inreq( nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16); str_p = inreq->list_of_streams; + if (nums * sizeof(__u16) + sizeof(struct sctp_strreset_outreq) > + SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_reconf_chunk)) + goto out; for (i = 0; i < nums; i++) { if (ntohs(str_p[i]) >= stream->outcnt) { result = SCTP_STRRESET_ERR_WRONG_SSN; -- 2.53.0