Commit 2c08522e authored by Tim Gardner's avatar Tim Gardner Committed by Patrick McHardy

netfilter: xt_recent: fix buffer overflow

e->index overflows e->stamps[] every ip_pkt_list_tot packets.

Consider the case when ip_pkt_list_tot==1; the first packet received is stored
in e->stamps[0] and e->index is initialized to 1. The next received packet
timestamp is then stored at e->stamps[1] in recent_entry_update(),
a buffer overflow because the maximum e->stamps[] index is 0.
Signed-off-by: default avatarTim Gardner <tim.gardner@canonical.com>
Cc: stable@kernel.org
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 9e2dcf72
...@@ -177,10 +177,10 @@ recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr, ...@@ -177,10 +177,10 @@ recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
static void recent_entry_update(struct recent_table *t, struct recent_entry *e) static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
{ {
e->index %= ip_pkt_list_tot;
e->stamps[e->index++] = jiffies; e->stamps[e->index++] = jiffies;
if (e->index > e->nstamps) if (e->index > e->nstamps)
e->nstamps = e->index; e->nstamps = e->index;
e->index %= ip_pkt_list_tot;
list_move_tail(&e->lru_list, &t->lru_list); list_move_tail(&e->lru_list, &t->lru_list);
} }
......
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