From: Gavrilov Ilia Ilia.Gavrilov@infotecs.ru
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 Ilia.Gavrilov@infotecs.ru Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/ipset/ip_set_bitmap_ip.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -299,8 +299,8 @@ bitmap_ip_create(struct net *net, struct 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;