diff options
| author | Florian Westphal <fw@strlen.de> | 2016-04-01 14:17:23 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-04-14 00:30:35 +0200 |
| commit | 7d35812c3214afa5b37a675113555259cfd67b98 (patch) | |
| tree | bf58d19850c9a9da5c42e5f6a66588a6b5972059 /net/ipv4 | |
| parent | netfilter: x_tables: validate targets of jumps (diff) | |
| download | linux-7d35812c3214afa5b37a675113555259cfd67b98.tar.xz linux-7d35812c3214afa5b37a675113555259cfd67b98.zip | |
netfilter: x_tables: add and use xt_check_entry_offsets
Currently arp/ip and ip6tables each implement a short helper to check that
the target offset is large enough to hold one xt_entry_target struct and
that t->u.target_size fits within the current rule.
Unfortunately these checks are not sufficient.
To avoid adding new tests to all of ip/ip6/arptables move the current
checks into a helper, then extend this helper in followup patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/netfilter/arp_tables.c | 11 | ||||
| -rw-r--r-- | net/ipv4/netfilter/ip_tables.c | 12 |
2 files changed, 2 insertions, 21 deletions
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index ec37f7c3a033..74668c1d3243 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -496,19 +496,10 @@ next: static inline int check_entry(const struct arpt_entry *e) { - const struct xt_entry_target *t; - if (!arp_checkentry(&e->arp)) return -EINVAL; - if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset) - return -EINVAL; - - t = arpt_get_target_c(e); - if (e->target_offset + t->u.target_size > e->next_offset) - return -EINVAL; - - return 0; + return xt_check_entry_offsets(e, e->target_offset, e->next_offset); } static inline int check_target(struct arpt_entry *e, const char *name) diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 503038ea7735..71c204d4ca5f 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -590,20 +590,10 @@ static void cleanup_match(struct xt_entry_match *m, struct net *net) static int check_entry(const struct ipt_entry *e) { - const struct xt_entry_target *t; - if (!ip_checkentry(&e->ip)) return -EINVAL; - if (e->target_offset + sizeof(struct xt_entry_target) > - e->next_offset) - return -EINVAL; - - t = ipt_get_target_c(e); - if (e->target_offset + t->u.target_size > e->next_offset) - return -EINVAL; - - return 0; + return xt_check_entry_offsets(e, e->target_offset, e->next_offset); } static int |