[NET]: Fix fib_rules compatibility breakage
Based upon a patch from Patrick McHardy.
The fib_rules netlink attribute policy introduced in 2.6.19 broke
userspace compatibilty. When specifying a rule with "from all"
or "to all", iproute adds a zero byte long netlink attribute,
but the policy requires all addresses to have a size equal to
sizeof(struct in_addr)/sizeof(struct in6_addr), resulting in a
validation error.
Check attribute length of FRA_SRC/FRA_DST in the generic framework
by letting the family specific rules implementation provide the
length of an address. Report an error if address length is non
zero but no address attribute is provided. Fix actual bug by
checking address length for non-zero instead of relying on
availability of attribute.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index bc3c264..d585ea9 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -34,6 +34,7 @@
int family;
struct list_head list;
int rule_size;
+ int addr_size;
int (*action)(struct fib_rule *,
struct flowi *, int,
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 3aea4e8..d011819 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -152,6 +152,28 @@
EXPORT_SYMBOL_GPL(fib_rules_lookup);
+static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
+ struct fib_rules_ops *ops)
+{
+ int err = -EINVAL;
+
+ if (frh->src_len)
+ if (tb[FRA_SRC] == NULL ||
+ frh->src_len > (ops->addr_size * 8) ||
+ nla_len(tb[FRA_SRC]) != ops->addr_size)
+ goto errout;
+
+ if (frh->dst_len)
+ if (tb[FRA_DST] == NULL ||
+ frh->dst_len > (ops->addr_size * 8) ||
+ nla_len(tb[FRA_DST]) != ops->addr_size)
+ goto errout;
+
+ err = 0;
+errout:
+ return err;
+}
+
int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
struct fib_rule_hdr *frh = nlmsg_data(nlh);
@@ -173,6 +195,10 @@
if (err < 0)
goto errout;
+ err = validate_rulemsg(frh, tb, ops);
+ if (err < 0)
+ goto errout;
+
rule = kzalloc(ops->rule_size, GFP_KERNEL);
if (rule == NULL) {
err = -ENOMEM;
@@ -260,6 +286,10 @@
if (err < 0)
goto errout;
+ err = validate_rulemsg(frh, tb, ops);
+ if (err < 0)
+ goto errout;
+
list_for_each_entry(rule, ops->rules_list, list) {
if (frh->action && (frh->action != rule->action))
continue;
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index b6c98ac..5e86dd5 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -109,8 +109,6 @@
static struct nla_policy dn_fib_rule_policy[FRA_MAX+1] __read_mostly = {
FRA_GENERIC_POLICY,
- [FRA_SRC] = { .type = NLA_U16 },
- [FRA_DST] = { .type = NLA_U16 },
};
static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
@@ -133,7 +131,7 @@
int err = -EINVAL;
struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
- if (frh->src_len > 16 || frh->dst_len > 16 || frh->tos)
+ if (frh->tos)
goto errout;
if (rule->table == RT_TABLE_UNSPEC) {
@@ -150,10 +148,10 @@
}
}
- if (tb[FRA_SRC])
+ if (frh->src_len)
r->src = nla_get_le16(tb[FRA_SRC]);
- if (tb[FRA_DST])
+ if (frh->dst_len)
r->dst = nla_get_le16(tb[FRA_DST]);
r->src_len = frh->src_len;
@@ -176,10 +174,10 @@
if (frh->dst_len && (r->dst_len != frh->dst_len))
return 0;
- if (tb[FRA_SRC] && (r->src != nla_get_le16(tb[FRA_SRC])))
+ if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
return 0;
- if (tb[FRA_DST] && (r->dst != nla_get_le16(tb[FRA_DST])))
+ if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
return 0;
return 1;
@@ -249,6 +247,7 @@
static struct fib_rules_ops dn_fib_rules_ops = {
.family = AF_DECnet,
.rule_size = sizeof(struct dn_fib_rule),
+ .addr_size = sizeof(u16),
.action = dn_fib_rule_action,
.match = dn_fib_rule_match,
.configure = dn_fib_rule_configure,
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index b837c33..c660c07 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -171,8 +171,6 @@
static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
FRA_GENERIC_POLICY,
- [FRA_SRC] = { .type = NLA_U32 },
- [FRA_DST] = { .type = NLA_U32 },
[FRA_FLOW] = { .type = NLA_U32 },
};
@@ -183,8 +181,7 @@
int err = -EINVAL;
struct fib4_rule *rule4 = (struct fib4_rule *) rule;
- if (frh->src_len > 32 || frh->dst_len > 32 ||
- (frh->tos & ~IPTOS_TOS_MASK))
+ if (frh->tos & ~IPTOS_TOS_MASK)
goto errout;
if (rule->table == RT_TABLE_UNSPEC) {
@@ -201,10 +198,10 @@
}
}
- if (tb[FRA_SRC])
+ if (frh->src_len)
rule4->src = nla_get_be32(tb[FRA_SRC]);
- if (tb[FRA_DST])
+ if (frh->dst_len)
rule4->dst = nla_get_be32(tb[FRA_DST]);
#ifdef CONFIG_NET_CLS_ROUTE
@@ -242,10 +239,10 @@
return 0;
#endif
- if (tb[FRA_SRC] && (rule4->src != nla_get_be32(tb[FRA_SRC])))
+ if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
return 0;
- if (tb[FRA_DST] && (rule4->dst != nla_get_be32(tb[FRA_DST])))
+ if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
return 0;
return 1;
@@ -309,6 +306,7 @@
static struct fib_rules_ops fib4_rules_ops = {
.family = AF_INET,
.rule_size = sizeof(struct fib4_rule),
+ .addr_size = sizeof(u32),
.action = fib4_rule_action,
.match = fib4_rule_match,
.configure = fib4_rule_configure,
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 0862809..ea3035b 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -131,8 +131,6 @@
static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
FRA_GENERIC_POLICY,
- [FRA_SRC] = { .len = sizeof(struct in6_addr) },
- [FRA_DST] = { .len = sizeof(struct in6_addr) },
};
static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
@@ -142,9 +140,6 @@
int err = -EINVAL;
struct fib6_rule *rule6 = (struct fib6_rule *) rule;
- if (frh->src_len > 128 || frh->dst_len > 128)
- goto errout;
-
if (rule->action == FR_ACT_TO_TBL) {
if (rule->table == RT6_TABLE_UNSPEC)
goto errout;
@@ -155,11 +150,11 @@
}
}
- if (tb[FRA_SRC])
+ if (frh->src_len)
nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
sizeof(struct in6_addr));
- if (tb[FRA_DST])
+ if (frh->dst_len)
nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
sizeof(struct in6_addr));
@@ -186,11 +181,11 @@
if (frh->tos && (rule6->tclass != frh->tos))
return 0;
- if (tb[FRA_SRC] &&
+ if (frh->src_len &&
nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
return 0;
- if (tb[FRA_DST] &&
+ if (frh->dst_len &&
nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
return 0;
@@ -240,6 +235,7 @@
static struct fib_rules_ops fib6_rules_ops = {
.family = AF_INET6,
.rule_size = sizeof(struct fib6_rule),
+ .addr_size = sizeof(struct in6_addr),
.action = fib6_rule_action,
.match = fib6_rule_match,
.configure = fib6_rule_configure,
