linux-sctp.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
	Ilja Van Sprundel <ivansprundel@ioactive.com>,
	"David S . Miller" <davem@davemloft.net>,
	Sasha Levin <sashal@kernel.org>,
	linux-sctp@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 45/45] sctp: add size validation when walking chunks
Date: Tue,  6 Jul 2021 07:27:49 -0400	[thread overview]
Message-ID: <20210706112749.2065541-45-sashal@kernel.org> (raw)
In-Reply-To: <20210706112749.2065541-1-sashal@kernel.org>

From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

[ Upstream commit 50619dbf8db77e98d821d615af4f634d08e22698 ]

The first chunk in a packet is ensured to be present at the beginning of
sctp_rcv(), as a packet needs to have at least 1 chunk. But the second
one, may not be completely available and ch->length can be over
uninitialized memory.

Fix here is by only trying to walk on the next chunk if there is enough to
hold at least the header, and then proceed with the ch->length validation
that is already there.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 7380f0a5949b..1af35b69e99e 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -1197,7 +1197,7 @@ static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net,
 
 		ch = (struct sctp_chunkhdr *)ch_end;
 		chunk_num++;
-	} while (ch_end < skb_tail_pointer(skb));
+	} while (ch_end + sizeof(*ch) < skb_tail_pointer(skb));
 
 	return asoc;
 }
-- 
2.30.2


      parent reply	other threads:[~2021-07-06 11:48 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210706112749.2065541-1-sashal@kernel.org>
2021-07-06 11:27 ` [PATCH AUTOSEL 4.14 44/45] sctp: validate from_addr_param return Sasha Levin
2021-07-06 11:27 ` Sasha Levin [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210706112749.2065541-45-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=davem@davemloft.net \
    --cc=ivansprundel@ioactive.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sctp@vger.kernel.org \
    --cc=marcelo.leitner@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --subject='Re: [PATCH AUTOSEL 4.14 45/45] sctp: add size validation when walking chunks' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).