From 2b33d6ffa9e38f344418976b06057e2fc2aa9e2a Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Thu, 17 Dec 2020 11:53:40 +0300 Subject: [PATCH] netfilter: ipset: fixes possible oops in mtype_resize currently mtype_resize() can cause oops t = ip_set_alloc(htable_size(htable_bits)); if (!t) { ret = -ENOMEM; goto out; } t->hregion = ip_set_alloc(ahash_sizeof_regions(htable_bits)); Increased htable_bits can force htable_size() to return 0. In own turn ip_set_alloc(0) returns not 0 but ZERO_SIZE_PTR, so follwoing access to t->hregion should trigger an OOPS. Signed-off-by: Vasily Averin Acked-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_hash_gen.h | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index 5f1208ad049e..1e7dddf824ae 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -640,7 +640,7 @@ mtype_resize(struct ip_set *set, bool retried) struct htype *h = set->data; struct htable *t, *orig; u8 htable_bits; - size_t dsize = set->dsize; + size_t hsize, dsize = set->dsize; #ifdef IP_SET_HASH_WITH_NETS u8 flags; struct mtype_elem *tmp; @@ -664,14 +664,12 @@ mtype_resize(struct ip_set *set, bool retried) retry: ret = 0; htable_bits++; - if (!htable_bits) { - /* In case we have plenty of memory :-) */ - pr_warn("Cannot increase the hashsize of set %s further\n", - set->name); - ret = -IPSET_ERR_HASH_FULL; - goto out; - } - t = ip_set_alloc(htable_size(htable_bits)); + if (!htable_bits) + goto hbwarn; + hsize = htable_size(htable_bits); + if (!hsize) + goto hbwarn; + t = ip_set_alloc(hsize); if (!t) { ret = -ENOMEM; goto out; @@ -813,6 +811,12 @@ cleanup: if (ret == -EAGAIN) goto retry; goto out; + +hbwarn: + /* In case we have plenty of memory :-) */ + pr_warn("Cannot increase the hashsize of set %s further\n", set->name); + ret = -IPSET_ERR_HASH_FULL; + goto out; } /* Get the current number of elements and ext_size in the set */