From: Dan Carpenter <dan.carpenter@linaro.org>
Date: Mon, 10 Mar 2025 07:45:53 +0000 (+0300)
Subject: ipvs: prevent integer overflow in do_ip_vs_get_ctl()
X-Git-Tag: v5.10.236~212
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4c384a66084e7a99df526d0292ab0743f0d46038;p=thirdparty%2Fkernel%2Fstable.git

ipvs: prevent integer overflow in do_ip_vs_get_ctl()

[ Upstream commit 80b78c39eb86e6b55f56363b709eb817527da5aa ]

The get->num_services variable is an unsigned int which is controlled by
the user.  The struct_size() function ensures that the size calculation
does not overflow an unsigned long, however, we are saving the result to
an int so the calculation can overflow.

Both "len" and "get->num_services" come from the user.  This check is
just a sanity check to help the user and ensure they are using the API
correctly.  An integer overflow here is not a big deal.  This has no
security impact.

Save the result from struct_size() type size_t to fix this integer
overflow bug.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index d0b64c36471d5..fb9f1badeddbf 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -2852,12 +2852,12 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 	case IP_VS_SO_GET_SERVICES:
 	{
 		struct ip_vs_get_services *get;
-		int size;
+		size_t size;
 
 		get = (struct ip_vs_get_services *)arg;
 		size = struct_size(get, entrytable, get->num_services);
 		if (*len != size) {
-			pr_err("length: %u != %u\n", *len, size);
+			pr_err("length: %u != %zu\n", *len, size);
 			ret = -EINVAL;
 			goto out;
 		}
@@ -2893,12 +2893,12 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
 	case IP_VS_SO_GET_DESTS:
 	{
 		struct ip_vs_get_dests *get;
-		int size;
+		size_t size;
 
 		get = (struct ip_vs_get_dests *)arg;
 		size = struct_size(get, entrytable, get->num_dests);
 		if (*len != size) {
-			pr_err("length: %u != %u\n", *len, size);
+			pr_err("length: %u != %zu\n", *len, size);
 			ret = -EINVAL;
 			goto out;
 		}