Commit d157bd76 authored Mar 10, 2016 by Florian Westphal Committed by Pablo Neira Ayuso Mar 12, 2016

netfilter: x_tables: check for size overflow



Ben Hawkes says:
 integer overflow in xt_alloc_table_info, which on 32-bit systems can
 lead to small structure allocation and a copy_from_user based heap
 corruption.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent f0716cd6

net/netfilter/x_tables.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -659,6 +659,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size)
		struct xt_table_info *info = NULL;
		size_t sz = sizeof(*info) + size;

		if (sz < sizeof(*info))
		return NULL;

		/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
		if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
		return NULL;