xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

netfilter: x_tables: add and use xt_check_entry_offsets

Browse Source 
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>
This commit is contained in:
Florian Westphal
2016-04-01 14:17:23 +02:00
committed by Pablo Neira Ayuso
parent 3647234101
commit 7d35812c32
5 changed files with 41 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
net/ipv4/netfilter/arp_tables.c
View File

@@ -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)

12
net/ipv4/netfilter/ip_tables.c
View File

@@ -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