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 BB1B52566 for ; Tue, 18 Apr 2023 12:27:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EB14C433D2; Tue, 18 Apr 2023 12:27:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681820862; bh=gNijpVa9stuBi3k1FX5R8nNVbXTK4Nx9I3v+eEZ0G4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ra7y4Wuxvji5kLLgVr+UCHINtomq4BsB0Ch9/NMm2I3+2Y2Z3ZDvSDVeCA5yutrDW Xrtu0EofkxIwzqzfn/RQ8q2JpvbCRsf3D6vznFDGTJwxDMlkQtcsaicpul3JxqdDB2 8GVz2C8wsao2ZXivJKhOCKe11BT+WT+4Co0r2qyw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xin Long , Paolo Abeni , Sasha Levin Subject: [PATCH 4.19 39/57] sctp: fix a potential overflow in sctp_ifwdtsn_skip Date: Tue, 18 Apr 2023 14:21:39 +0200 Message-Id: <20230418120300.096512102@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120258.713853188@linuxfoundation.org> References: <20230418120258.713853188@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Xin Long [ Upstream commit 32832a2caf82663870126c5186cf8f86c8b2a649 ] Currently, when traversing ifwdtsn skips with _sctp_walk_ifwdtsn, it only checks the pos against the end of the chunk. However, the data left for the last pos may be < sizeof(struct sctp_ifwdtsn_skip), and dereference it as struct sctp_ifwdtsn_skip may cause coverflow. This patch fixes it by checking the pos against "the end of the chunk - sizeof(struct sctp_ifwdtsn_skip)" in sctp_ifwdtsn_skip, similar to sctp_fwdtsn_skip. Fixes: 0fc2ea922c8a ("sctp: implement validate_ftsn for sctp_stream_interleave") Signed-off-by: Xin Long Link: https://lore.kernel.org/r/2a71bffcd80b4f2c61fac6d344bb2f11c8fd74f7.1681155810.git.lucien.xin@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/sctp/stream_interleave.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sctp/stream_interleave.c b/net/sctp/stream_interleave.c index 0a78cdf864633..3290e6f5b6c6c 100644 --- a/net/sctp/stream_interleave.c +++ b/net/sctp/stream_interleave.c @@ -1151,7 +1151,8 @@ static void sctp_generate_iftsn(struct sctp_outq *q, __u32 ctsn) #define _sctp_walk_ifwdtsn(pos, chunk, end) \ for (pos = chunk->subh.ifwdtsn_hdr->skip; \ - (void *)pos < (void *)chunk->subh.ifwdtsn_hdr->skip + (end); pos++) + (void *)pos <= (void *)chunk->subh.ifwdtsn_hdr->skip + (end) - \ + sizeof(struct sctp_ifwdtsn_skip); pos++) #define sctp_walk_ifwdtsn(pos, ch) \ _sctp_walk_ifwdtsn((pos), (ch), ntohs((ch)->chunk_hdr->length) - \ -- 2.39.2