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netfilter: ipset: Limit the maximal range of consecutive elements to …
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…add/delete

The range size of consecutive elements were not limited. Thus one could
define a huge range which may result soft lockup errors due to the long
execution time. Now the range size is limited to 2^20 entries.

Reported-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Jozsef Kadlecsik authored and Pablo Neira Ayuso committed Aug 4, 2021
1 parent c7d1022 commit 5f7b51b
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Showing 11 changed files with 88 additions and 7 deletions.
3 changes: 3 additions & 0 deletions include/linux/netfilter/ipset/ip_set.h
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Original file line number Diff line number Diff line change
Expand Up @@ -196,6 +196,9 @@ struct ip_set_region {
u32 elements; /* Number of elements vs timeout */
};

/* Max range where every element is added/deleted in one step */
#define IPSET_MAX_RANGE (1<<20)

/* The max revision number supported by any set type + 1 */
#define IPSET_REVISION_MAX 9

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9 changes: 8 additions & 1 deletion net/netfilter/ipset/ip_set_hash_ip.c
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Original file line number Diff line number Diff line change
Expand Up @@ -132,8 +132,11 @@ hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
if (ret)
return ret;
if (ip > ip_to)
if (ip > ip_to) {
if (ip_to == 0)
return -IPSET_ERR_HASH_ELEM;
swap(ip, ip_to);
}
} else if (tb[IPSET_ATTR_CIDR]) {
u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);

Expand All @@ -144,6 +147,10 @@ hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],

hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);

/* 64bit division is not allowed on 32bit */
if (((u64)ip_to - ip + 1) >> (32 - h->netmask) > IPSET_MAX_RANGE)
return -ERANGE;

if (retried) {
ip = ntohl(h->next.ip);
e.ip = htonl(ip);
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10 changes: 9 additions & 1 deletion net/netfilter/ipset/ip_set_hash_ipmark.c
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Original file line number Diff line number Diff line change
Expand Up @@ -121,6 +121,8 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[],

e.mark = ntohl(nla_get_be32(tb[IPSET_ATTR_MARK]));
e.mark &= h->markmask;
if (e.mark == 0 && e.ip == 0)
return -IPSET_ERR_HASH_ELEM;

if (adt == IPSET_TEST ||
!(tb[IPSET_ATTR_IP_TO] || tb[IPSET_ATTR_CIDR])) {
Expand All @@ -133,8 +135,11 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[],
ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
if (ret)
return ret;
if (ip > ip_to)
if (ip > ip_to) {
if (e.mark == 0 && ip_to == 0)
return -IPSET_ERR_HASH_ELEM;
swap(ip, ip_to);
}
} else if (tb[IPSET_ATTR_CIDR]) {
u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);

Expand All @@ -143,6 +148,9 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[],
ip_set_mask_from_to(ip, ip_to, cidr);
}

if (((u64)ip_to - ip + 1) > IPSET_MAX_RANGE)
return -ERANGE;

if (retried)
ip = ntohl(h->next.ip);
for (; ip <= ip_to; ip++) {
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3 changes: 3 additions & 0 deletions net/netfilter/ipset/ip_set_hash_ipport.c
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Original file line number Diff line number Diff line change
Expand Up @@ -173,6 +173,9 @@ hash_ipport4_uadt(struct ip_set *set, struct nlattr *tb[],
swap(port, port_to);
}

if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
return -ERANGE;

if (retried)
ip = ntohl(h->next.ip);
for (; ip <= ip_to; ip++) {
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3 changes: 3 additions & 0 deletions net/netfilter/ipset/ip_set_hash_ipportip.c
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Original file line number Diff line number Diff line change
Expand Up @@ -180,6 +180,9 @@ hash_ipportip4_uadt(struct ip_set *set, struct nlattr *tb[],
swap(port, port_to);
}

if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
return -ERANGE;

if (retried)
ip = ntohl(h->next.ip);
for (; ip <= ip_to; ip++) {
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3 changes: 3 additions & 0 deletions net/netfilter/ipset/ip_set_hash_ipportnet.c
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Original file line number Diff line number Diff line change
Expand Up @@ -253,6 +253,9 @@ hash_ipportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
swap(port, port_to);
}

if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
return -ERANGE;

ip2_to = ip2_from;
if (tb[IPSET_ATTR_IP2_TO]) {
ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP2_TO], &ip2_to);
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11 changes: 10 additions & 1 deletion net/netfilter/ipset/ip_set_hash_net.c
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Original file line number Diff line number Diff line change
Expand Up @@ -140,7 +140,7 @@ hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
ipset_adtfn adtfn = set->variant->adt[adt];
struct hash_net4_elem e = { .cidr = HOST_MASK };
struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
u32 ip = 0, ip_to = 0;
u32 ip = 0, ip_to = 0, ipn, n = 0;
int ret;

if (tb[IPSET_ATTR_LINENO])
Expand Down Expand Up @@ -188,6 +188,15 @@ hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
if (ip + UINT_MAX == ip_to)
return -IPSET_ERR_HASH_RANGE;
}
ipn = ip;
do {
ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr);
n++;
} while (ipn++ < ip_to);

if (n > IPSET_MAX_RANGE)
return -ERANGE;

if (retried)
ip = ntohl(h->next.ip);
do {
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10 changes: 9 additions & 1 deletion net/netfilter/ipset/ip_set_hash_netiface.c
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Original file line number Diff line number Diff line change
Expand Up @@ -202,7 +202,7 @@ hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
ipset_adtfn adtfn = set->variant->adt[adt];
struct hash_netiface4_elem e = { .cidr = HOST_MASK, .elem = 1 };
struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
u32 ip = 0, ip_to = 0;
u32 ip = 0, ip_to = 0, ipn, n = 0;
int ret;

if (tb[IPSET_ATTR_LINENO])
Expand Down Expand Up @@ -256,6 +256,14 @@ hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
} else {
ip_set_mask_from_to(ip, ip_to, e.cidr);
}
ipn = ip;
do {
ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr);
n++;
} while (ipn++ < ip_to);

if (n > IPSET_MAX_RANGE)
return -ERANGE;

if (retried)
ip = ntohl(h->next.ip);
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16 changes: 15 additions & 1 deletion net/netfilter/ipset/ip_set_hash_netnet.c
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Original file line number Diff line number Diff line change
Expand Up @@ -168,7 +168,8 @@ hash_netnet4_uadt(struct ip_set *set, struct nlattr *tb[],
struct hash_netnet4_elem e = { };
struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
u32 ip = 0, ip_to = 0;
u32 ip2 = 0, ip2_from = 0, ip2_to = 0;
u32 ip2 = 0, ip2_from = 0, ip2_to = 0, ipn;
u64 n = 0, m = 0;
int ret;

if (tb[IPSET_ATTR_LINENO])
Expand Down Expand Up @@ -244,6 +245,19 @@ hash_netnet4_uadt(struct ip_set *set, struct nlattr *tb[],
} else {
ip_set_mask_from_to(ip2_from, ip2_to, e.cidr[1]);
}
ipn = ip;
do {
ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr[0]);
n++;
} while (ipn++ < ip_to);
ipn = ip2_from;
do {
ipn = ip_set_range_to_cidr(ipn, ip2_to, &e.cidr[1]);
m++;
} while (ipn++ < ip2_to);

if (n*m > IPSET_MAX_RANGE)
return -ERANGE;

if (retried) {
ip = ntohl(h->next.ip[0]);
Expand Down
11 changes: 10 additions & 1 deletion net/netfilter/ipset/ip_set_hash_netport.c
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Original file line number Diff line number Diff line change
Expand Up @@ -158,7 +158,8 @@ hash_netport4_uadt(struct ip_set *set, struct nlattr *tb[],
ipset_adtfn adtfn = set->variant->adt[adt];
struct hash_netport4_elem e = { .cidr = HOST_MASK - 1 };
struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
u32 port, port_to, p = 0, ip = 0, ip_to = 0;
u32 port, port_to, p = 0, ip = 0, ip_to = 0, ipn;
u64 n = 0;
bool with_ports = false;
u8 cidr;
int ret;
Expand Down Expand Up @@ -235,6 +236,14 @@ hash_netport4_uadt(struct ip_set *set, struct nlattr *tb[],
} else {
ip_set_mask_from_to(ip, ip_to, e.cidr + 1);
}
ipn = ip;
do {
ipn = ip_set_range_to_cidr(ipn, ip_to, &cidr);
n++;
} while (ipn++ < ip_to);

if (n*(port_to - port + 1) > IPSET_MAX_RANGE)
return -ERANGE;

if (retried) {
ip = ntohl(h->next.ip);
Expand Down
16 changes: 15 additions & 1 deletion net/netfilter/ipset/ip_set_hash_netportnet.c
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Original file line number Diff line number Diff line change
Expand Up @@ -182,7 +182,8 @@ hash_netportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
struct hash_netportnet4_elem e = { };
struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
u32 ip = 0, ip_to = 0, p = 0, port, port_to;
u32 ip2_from = 0, ip2_to = 0, ip2;
u32 ip2_from = 0, ip2_to = 0, ip2, ipn;
u64 n = 0, m = 0;
bool with_ports = false;
int ret;

Expand Down Expand Up @@ -284,6 +285,19 @@ hash_netportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
} else {
ip_set_mask_from_to(ip2_from, ip2_to, e.cidr[1]);
}
ipn = ip;
do {
ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr[0]);
n++;
} while (ipn++ < ip_to);
ipn = ip2_from;
do {
ipn = ip_set_range_to_cidr(ipn, ip2_to, &e.cidr[1]);
m++;
} while (ipn++ < ip2_to);

if (n*m*(port_to - port + 1) > IPSET_MAX_RANGE)
return -ERANGE;

if (retried) {
ip = ntohl(h->next.ip[0]);
Expand Down

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