netfilter: conntrack: avoid integer overflow when resizing

Can overflow so we might allocate very small table when bucket count is
high on a 32bit platform.

Note: resize is only possible from init_netns.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2016-04-24 01:18:21 +02:00 committed by Pablo Neira Ayuso
parent 62131e5d73
commit 9cc1c73ad6

View File

@ -1601,8 +1601,15 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
unsigned int nr_slots, i;
size_t sz;
if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head)))
return NULL;
BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head));
nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head));
if (nr_slots > (UINT_MAX / sizeof(struct hlist_nulls_head)))
return NULL;
sz = nr_slots * sizeof(struct hlist_nulls_head);
hash = (void *)__get_free_pages(GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO,
get_order(sz));