Messages in this thread Patch in this message | | | From | Gavrilov Ilia <> | Subject | [PATCH] netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. | Date | Mon, 9 Jan 2023 11:54:02 +0000 |
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When first_ip is 0, last_ip is 0xFFFFFFF, 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> --- net/netfilter/ipset/ip_set_bitmap_ip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c index a8ce04a4bb72..b8f0fb37378f 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -309,7 +309,7 @@ bitmap_ip_create(struct net *net, struct ip_set *set, struct nlattr *tb[], pr_debug("mask_bits %u, netmask %u\n", mask_bits, netmask); hosts = 2 << (32 - netmask - 1); - elements = 2 << (netmask - mask_bits - 1); + elements = 2UL << (netmask - mask_bits - 1); } if (elements > IPSET_BITMAP_MAX_RANGE + 1) return -IPSET_ERR_BITMAP_RANGE_SIZE; -- 2.30.2
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