From: Gavrilov Ilia Date: Sat, 28 Jan 2023 18:09:52 +0000 (+0100) Subject: netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. X-Git-Tag: v7.18~19 X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=f9a5f712132273139473cb322c3155375a1d1836;p=thirdparty%2Fipset.git netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. When first_ip is 0, last_ip is 0xFFFFFFFF, and netmask is 31, the value of an arithmetic expression 2 << (netmask - mask_bits - 1) is subject to overflow due to a failure casting operands to a larger data type before performing the arithmetic. Note that it's harmless since the value will be checked at the next step. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE. Fixes: b9fed748185a ("netfilter: ipset: Check and reject crazy /0 input parameters") Signed-off-by: Ilia.Gavrilov Signed-off-by: Jozsef Kadlecsik --- diff --git a/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c b/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c index c4886639..f37169c7 100644 --- a/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -312,8 +312,8 @@ bitmap_ip_create(struct net *net, struct ip_set *set, struct nlattr *tb[], return -IPSET_ERR_BITMAP_RANGE; pr_debug("mask_bits %u, netmask %u\n", mask_bits, netmask); - hosts = 2 << (32 - netmask - 1); - elements = 2 << (netmask - mask_bits - 1); + hosts = 2U << (32 - netmask - 1); + elements = 2UL << (netmask - mask_bits - 1); } if (elements > IPSET_BITMAP_MAX_RANGE + 1) return -IPSET_ERR_BITMAP_RANGE_SIZE;