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; }