From a7d51738e757c1ab94595e7d05594c61f0fb32ce Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Sat, 18 Jul 2009 14:52:58 +0200 Subject: netfilter: xtables: ignore unassigned hooks in check_entry_size_and_hooks The "hook_entry" and "underflow" array contains values even for hooks not provided, such as PREROUTING in conjunction with the "filter" table. Usually, the values point to whatever the next rule is. For the upcoming unconditionality and underflow checking patches however, we must not inspect that arbitrary rule. Skipping unassigned hooks seems like a good idea, also because newinfo->hook_entry and newinfo->underflow will then continue to have the poison value for detecting abnormalities. Signed-off-by: Jan Engelhardt --- net/ipv4/netfilter/ip_tables.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/ipv4/netfilter/ip_tables.c') diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 3431a771ff1f..6e7b7e8b80b1 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -714,6 +714,7 @@ check_entry_size_and_hooks(struct ipt_entry *e, unsigned char *limit, const unsigned int *hook_entries, const unsigned int *underflows, + unsigned int valid_hooks, unsigned int *i) { unsigned int h; @@ -733,6 +734,8 @@ check_entry_size_and_hooks(struct ipt_entry *e, /* Check hooks & underflows */ for (h = 0; h < NF_INET_NUMHOOKS; h++) { + if (!(valid_hooks & (1 << h))) + continue; if ((unsigned char *)e - base == hook_entries[h]) newinfo->hook_entry[h] = hook_entries[h]; if ((unsigned char *)e - base == underflows[h]) @@ -804,7 +807,7 @@ translate_table(const char *name, newinfo, entry0, entry0 + size, - hook_entries, underflows, &i); + hook_entries, underflows, valid_hooks, &i); if (ret != 0) return ret; -- cgit v1.2.3