This is a note to let you know that I've just added the patch titled netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: netfilter-ipset-fix-overflow-before-widen-in-the-bitmap_ip_create-function.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 9ea4b476cea1b7d461d16dda25ca3c7e616e2d15 Mon Sep 17 00:00:00 2001 From: Gavrilov Ilia <Ilia.Gavrilov@xxxxxxxxxxx> Date: Wed, 11 Jan 2023 11:57:39 +0000 Subject: netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. From: Gavrilov Ilia <Ilia.Gavrilov@xxxxxxxxxxx> 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@xxxxxxxxxxx> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -308,8 +308,8 @@ 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; Patches currently in stable-queue which might be from Ilia.Gavrilov@xxxxxxxxxxx are queue-6.1/netfilter-ipset-fix-overflow-before-widen-in-the-bitmap_ip_create-function.patch