[PATCH net] ipvs: prevent integer overflow in do_ip_vs_get_ctl()

[Dan Carpenter]

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.

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

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 net/netfilter/ipvs/ip_vs_ctl.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 7d13110ce188..801d65fd8a81 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3091,12 +3091,12 @@ 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 != %lu\n", *len, size);
 			ret = -EINVAL;
 			goto out;
 		}
@@ -3132,12 +3132,12 @@ 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 != %lu\n", *len, size);
 			ret = -EINVAL;
 			goto out;
 		}
-- 
2.47.2