Commit 2a43c4af authored by Phil Oester's avatar Phil Oester Committed by David S. Miller
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[NETFILTER]: Fix recent match jiffies wrap mismatches



Around jiffies wrap time (i.e. within first 5 mins after boot), recent
match rules which contain both --seconds and --hitcount arguments
experience false matches.

This is because the last_pkts array is filled with zeros on creation, and
when comparing 'now' to 0 (+ --seconds argument), time_before_eq thinks it
has found a hit.

Below patch adds a break if the packet value is zero.  This has the
unfortunate side effect of causing mismatches if a packet was received
when jiffies really was equal to zero.  The odds of that happening are
slim compared to the problems caused by not adding the break however.
Plus, the author used this same method just below, so it is "good enough".

This fixes netfilter bugs #383 and #395.
Signed-off-by: default avatarPhil Oester <kernel@linuxace.com>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 73f30602
......@@ -532,6 +532,7 @@ match(const struct sk_buff *skb,
}
if(info->seconds && info->hit_count) {
for(pkt_count = 0, hits_found = 0; pkt_count < ip_pkt_list_tot; pkt_count++) {
if(r_list[location].last_pkts[pkt_count] == 0) break;
if(time_before_eq(now,r_list[location].last_pkts[pkt_count]+info->seconds*HZ)) hits_found++;
}
if(hits_found >= info->hit_count) ans = !info->invert; else ans = info->invert;
......
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