From: Florian Westphal <fw@strlen.de>
To: <netfilter-devel@vger.kernel.org>
Cc: Florian Westphal <fw@strlen.de>
Subject: [PATCH nf 06/17] netfilter: x_tables: add compat version of xt_check_entry_offsets
Date: Fri, 1 Apr 2016 14:17:26 +0200 [thread overview]
Message-ID: <1459513057-30652-7-git-send-email-fw@strlen.de> (raw)
In-Reply-To: <1459513057-30652-1-git-send-email-fw@strlen.de>
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>
---
include/linux/netfilter/x_tables.h | 3 +++
net/ipv4/netfilter/arp_tables.c | 3 ++-
net/ipv4/netfilter/ip_tables.c | 3 ++-
net/ipv6/netfilter/ip6_tables.c | 3 ++-
net/netfilter/x_tables.c | 22 ++++++++++++++++++++++
5 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 0de0862..08de48b 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -494,6 +494,9 @@ 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 24ad92a..ab8952a 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1254,7 +1254,8 @@ 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 cdf1850..7d24c87 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1513,7 +1513,8 @@ 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 e378311..73eee7b 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1525,7 +1525,8 @@ 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 ec1b718..fa206ce 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -539,6 +539,27 @@ 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 */
/**
@@ -549,6 +570,7 @@ 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
--
2.7.3
next prev parent reply other threads:[~2016-04-01 12:17 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-01 12:17 [PATCH nf 00/17] netfilter: xtables: stricter ruleset validation Florian Westphal
2016-04-01 12:17 ` [PATCH nf 01/17] netfilter: x_tables: don't move to non-existent next rule Florian Westphal
2016-04-01 12:17 ` [PATCH nf 02/17] netfilter: x_tables: validate targets of jumps Florian Westphal
2016-04-01 12:24 ` Jan Engelhardt
2016-04-01 12:17 ` [PATCH nf 03/17] netfilter: x_tables: add and use xt_check_entry_offsets Florian Westphal
2016-04-01 12:17 ` [PATCH nf 04/17] netfilter: x_tables: kill check_entry helper Florian Westphal
2016-04-01 12:17 ` [PATCH nf 05/17] netfilter: x_tables: assert minimum target size Florian Westphal
2016-04-01 12:17 ` Florian Westphal [this message]
2016-04-01 12:17 ` [PATCH nf 07/17] netfilter: x_tables: check standard target size too Florian Westphal
2016-04-01 12:17 ` [PATCH nf 08/17] netfilter: x_tables: check for bogus target offset Florian Westphal
2016-04-01 12:17 ` [PATCH nf 09/17] netfilter: x_tables: validate all offsets and sizes in a rule Florian Westphal
2016-04-01 12:17 ` [PATCH nf 10/17] netfilter: ip_tables: simplify translate_compat_table args Florian Westphal
2016-04-01 12:17 ` [PATCH nf 11/17] netfilter: ip6_tables: " Florian Westphal
2016-04-01 12:17 ` [PATCH nf 12/17] netfilter: arp_tables: " Florian Westphal
2016-04-01 12:17 ` [PATCH nf 13/17] netfilter: x_tables: xt_compat_match_from_user doesn't need a retval Florian Westphal
2016-04-01 12:17 ` [PATCH nf 14/17] netfilter: x_tables: do compat validation via translate_table Florian Westphal
2016-04-01 12:17 ` [PATCH nf 15/17] netfilter: x_tables: remove obsolete overflow check for compat case too Florian Westphal
2016-04-01 12:17 ` [PATCH nf 16/17] netfilter: x_tables: remove obsolete check Florian Westphal
2016-04-01 12:17 ` [PATCH nf 17/17] netfilter: x_tables: introduce and use xt_copy_counters_from_user Florian Westphal
2016-04-01 12:52 ` kbuild test robot
2016-04-01 13:06 ` kbuild test robot
2016-04-01 13:33 ` kbuild test robot
2016-04-01 13:37 ` [PATCH v2 " Florian Westphal
2016-04-08 11:58 ` [PATCH nf 00/17] netfilter: xtables: stricter ruleset validation Pablo Neira Ayuso
2016-04-08 11:59 ` Florian Westphal
2016-04-12 21:54 ` Pablo Neira Ayuso
2016-04-13 22:33 ` Pablo Neira Ayuso
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