[NETFILTER]: ebtables: don't compute gap before checking struct type
We cannot compute the gap until we know we have a 'struct ebt_entry' and
not 'struct ebt_entries'. Failure to check can cause crash.
Tested-by: Santiago Garcia Mantinan <manty@manty.net>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index bee558a4..6c84ccb 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -610,7 +610,7 @@
struct ebt_entry_target *t;
struct ebt_target *target;
unsigned int i, j, hook = 0, hookmask = 0;
- size_t gap = e->next_offset - e->target_offset;
+ size_t gap;
int ret;
/* don't mess with the struct ebt_entries */
@@ -660,6 +660,7 @@
if (ret != 0)
goto cleanup_watchers;
t = (struct ebt_entry_target *)(((char *)e) + e->target_offset);
+ gap = e->next_offset - e->target_offset;
target = find_target_lock(t->u.name, &ret, &ebt_mutex);
if (!target)
goto cleanup_watchers;