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authorEric Dumazet <edumazet@google.com>2021-05-06 05:53:50 -0700
committerPablo Neira Ayuso <pablo@netfilter.org>2021-05-07 10:01:39 +0200
commit6c8774a94e6ad26f29ef103c8671f55c255c6201 (patch)
tree1a14a9f80a7ed0347b7f1a7f3c51b12d5404f4e1
parenta54754ec9891830ba548e2010c889e3c8146e449 (diff)
netfilter: nftables: avoid potential overflows on 32bit arches
User space could ask for very large hash tables, we need to make sure our size computations wont overflow. nf_tables_newset() needs to double check the u64 size will fit into size_t field. Fixes: 0ed6389c483d ("netfilter: nf_tables: rename set implementations") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r--net/netfilter/nf_tables_api.c7
-rw-r--r--net/netfilter/nft_set_hash.c10
2 files changed, 10 insertions, 7 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 926da6ed8d51..d63d2d8f769c 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4184,6 +4184,7 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
unsigned char *udata;
struct nft_set *set;
struct nft_ctx ctx;
+ size_t alloc_size;
u64 timeout;
char *name;
int err, i;
@@ -4329,8 +4330,10 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
size = 0;
if (ops->privsize != NULL)
size = ops->privsize(nla, &desc);
-
- set = kvzalloc(sizeof(*set) + size + udlen, GFP_KERNEL);
+ alloc_size = sizeof(*set) + size + udlen;
+ if (alloc_size < size)
+ return -ENOMEM;
+ set = kvzalloc(alloc_size, GFP_KERNEL);
if (!set)
return -ENOMEM;
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 328f2ce32e4c..7b3d0a78c569 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -623,7 +623,7 @@ static u64 nft_hash_privsize(const struct nlattr * const nla[],
const struct nft_set_desc *desc)
{
return sizeof(struct nft_hash) +
- nft_hash_buckets(desc->size) * sizeof(struct hlist_head);
+ (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head);
}
static int nft_hash_init(const struct nft_set *set,
@@ -663,8 +663,8 @@ static bool nft_hash_estimate(const struct nft_set_desc *desc, u32 features,
return false;
est->size = sizeof(struct nft_hash) +
- nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
- desc->size * sizeof(struct nft_hash_elem);
+ (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
+ (u64)desc->size * sizeof(struct nft_hash_elem);
est->lookup = NFT_SET_CLASS_O_1;
est->space = NFT_SET_CLASS_O_N;
@@ -681,8 +681,8 @@ static bool nft_hash_fast_estimate(const struct nft_set_desc *desc, u32 features
return false;
est->size = sizeof(struct nft_hash) +
- nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
- desc->size * sizeof(struct nft_hash_elem);
+ (u64)nft_hash_buckets(desc->size) * sizeof(struct hlist_head) +
+ (u64)desc->size * sizeof(struct nft_hash_elem);
est->lookup = NFT_SET_CLASS_O_1;
est->space = NFT_SET_CLASS_O_N;

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