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authorFlorian Westphal <fw@strlen.de>2016-04-01 14:17:26 +0200
committerSasha Levin <sasha.levin@oracle.com>2016-07-12 08:48:32 -0400
commit7ef13f496d3bc0db5ce42451a6036c504cf6a7d6 (patch)
treefe631fc77c4d201f8c8e53c2b650cfbde826977f
parent37a6fed6bcd018561cf18ddef42f6f6e106b220e (diff)
downloadlinux-linaro-stable-7ef13f496d3bc0db5ce42451a6036c504cf6a7d6.tar.gz
netfilter: x_tables: add compat version of xt_check_entry_offsets
[ Upstream commit fc1221b3a163d1386d1052184202d5dc50d302d1 ] 32bit rulesets have different layout and alignment requirements, so once more integrity checks get added to xt_check_entry_offsets it will reject well-formed 32bit rulesets. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--include/linux/netfilter/x_tables.h3
-rw-r--r--net/ipv4/netfilter/arp_tables.c3
-rw-r--r--net/ipv4/netfilter/ip_tables.c3
-rw-r--r--net/ipv6/netfilter/ip6_tables.c3
-rw-r--r--net/netfilter/x_tables.c22
5 files changed, 31 insertions, 3 deletions
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index a2d150873721..81843aa42a15 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -435,6 +435,9 @@ void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
unsigned int *size);
int xt_compat_target_to_user(const struct xt_entry_target *t,
void __user **dstptr, unsigned int *size);
+int xt_compat_check_entry_offsets(const void *base,
+ unsigned int target_offset,
+ unsigned int next_offset);
#endif /* CONFIG_COMPAT */
#endif /* _X_TABLES_H */
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index dc5bd7a10457..6924de43808e 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1244,7 +1244,8 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
if (!arp_checkentry(&e->arp))
return -EINVAL;
- ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+ ret = xt_compat_check_entry_offsets(e, e->target_offset,
+ e->next_offset);
if (ret)
return ret;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index eaf84eeaf126..9488131b2b84 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1509,7 +1509,8 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
if (!ip_checkentry(&e->ip))
return -EINVAL;
- ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+ ret = xt_compat_check_entry_offsets(e,
+ e->target_offset, e->next_offset);
if (ret)
return ret;
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 0822d538361f..a23bf5386aea 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1521,7 +1521,8 @@ check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
if (!ip6_checkentry(&e->ipv6))
return -EINVAL;
- ret = xt_check_entry_offsets(e, e->target_offset, e->next_offset);
+ ret = xt_compat_check_entry_offsets(e,
+ e->target_offset, e->next_offset);
if (ret)
return ret;
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index f432ee7e4d6d..242245330ec3 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -541,6 +541,27 @@ int xt_compat_match_to_user(const struct xt_entry_match *m,
return 0;
}
EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
+
+int xt_compat_check_entry_offsets(const void *base,
+ unsigned int target_offset,
+ unsigned int next_offset)
+{
+ const struct compat_xt_entry_target *t;
+ const char *e = base;
+
+ if (target_offset + sizeof(*t) > next_offset)
+ return -EINVAL;
+
+ t = (void *)(e + target_offset);
+ if (t->u.target_size < sizeof(*t))
+ return -EINVAL;
+
+ if (target_offset + t->u.target_size > next_offset)
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL(xt_compat_check_entry_offsets);
#endif /* CONFIG_COMPAT */
/**
@@ -551,6 +572,7 @@ EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
* @next_offset: the arp/ip/ip6_t->next_offset
*
* validates that target_offset and next_offset are sane.
+ * Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version.
*
* The arp/ip/ip6t_entry structure @base must have passed following tests:
* - it must point to a valid memory location