From: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Date: Thu, 7 Mar 2024 14:23:50 +0000 (+0000)
Subject: net/x25: fix incorrect parameter validation in the x25_getsockopt() function
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d6eb8de2015f0c24822e47356f839167ebde2945;p=linux.git

net/x25: fix incorrect parameter validation in the x25_getsockopt() function

The 'len' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.

To fix the logic, check 'len' as read from 'optlen',
where the types of relevant variables are (signed) int.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index f7a7c7798c3b2..d18d51412cc00 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -460,12 +460,12 @@ static int x25_getsockopt(struct socket *sock, int level, int optname,
 	if (get_user(len, optlen))
 		goto out;
 
-	len = min_t(unsigned int, len, sizeof(int));
-
 	rc = -EINVAL;
 	if (len < 0)
 		goto out;
 
+	len = min_t(unsigned int, len, sizeof(int));
+
 	rc = -EFAULT;
 	if (put_user(len, optlen))
 		goto out;