Commit cfd6e7fe authored Jul 13, 2016 by Florian Westphal Committed by Greg Kroah-Hartman Sep 15, 2016

netfilter: x_tables: check for size overflow



[ Upstream commit d157bd761585605b7882935ffb86286919f62ea1 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c6d7c62c

net/netfilter/x_tables.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -897,6 +897,9 @@ 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;