netfilter: x_tables: check for size overflow

[ Upstream commit d157bd7615 ]

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>
This commit is contained in:
Florian Westphal 2016-08-30 00:35:04 -04:00 committed by Greg Kroah-Hartman
parent b54698f045
commit 61610c63fa

View File

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