From: Gavrilov Ilia Date: Wed, 11 Jan 2023 11:57:39 +0000 (+0000) Subject: netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=511cf17b2447fc41cfef8d71936e1fa53e395c1e;p=linux.git netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. commit 9ea4b476cea1b7d461d16dda25ca3c7e616e2d15 upstream. 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 Reviewed-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c index a8ce04a4bb72a..e4fa00abde6a2 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -308,8 +308,8 @@ 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;