From aaff23a95aea5f000895f50d90e91f1e2f727002 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 7 Jan 2010 18:33:18 +0100 Subject: [PATCH] netfilter: nf_ct_ftp: fix out of bounds read in update_nl_seq() As noticed by Dan Carpenter , update_nl_seq() currently contains an out of bounds read of the seq_aft_nl array when looking for the oldest sequence number position. Fix it to only compare valid positions. Cc: stable@kernel.org Signed-off-by: Patrick McHardy --- net/netfilter/nf_conntrack_ftp.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c index 38ea7ef3ccd2..f0732aa18e4f 100644 --- a/net/netfilter/nf_conntrack_ftp.c +++ b/net/netfilter/nf_conntrack_ftp.c @@ -323,24 +323,24 @@ static void update_nl_seq(struct nf_conn *ct, u32 nl_seq, struct nf_ct_ftp_master *info, int dir, struct sk_buff *skb) { - unsigned int i, oldest = NUM_SEQ_TO_REMEMBER; + unsigned int i, oldest; /* Look for oldest: if we find exact match, we're done. */ for (i = 0; i < info->seq_aft_nl_num[dir]; i++) { if (info->seq_aft_nl[dir][i] == nl_seq) return; - - if (oldest == info->seq_aft_nl_num[dir] || - before(info->seq_aft_nl[dir][i], - info->seq_aft_nl[dir][oldest])) - oldest = i; } if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) { info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq; - } else if (oldest != NUM_SEQ_TO_REMEMBER && - after(nl_seq, info->seq_aft_nl[dir][oldest])) { - info->seq_aft_nl[dir][oldest] = nl_seq; + } else { + if (before(info->seq_aft_nl[dir][0], info->seq_aft_nl[dir][1])) + oldest = 0; + else + oldest = 1; + + if (after(nl_seq, info->seq_aft_nl[dir][oldest])) + info->seq_aft_nl[dir][oldest] = nl_seq; } } -- 2.20.1