[PATCH net-next v2 6/6] net/x25: fix incorrect parameter validation in the x25_getsockopt() function

* [PATCH net-next v2 6/6] net/x25: fix incorrect parameter validation in the x25_getsockopt() function
       [not found] <20240307142030.2708698-1-Ilia.Gavrilov@infotecs.ru>
@ 2024-03-07 14:23 ` Gavrilov Ilia
  0 siblings, 0 replies; only message in thread
From: Gavrilov Ilia @ 2024-03-07 14:23 UTC (permalink / raw)
  To: Martin Schiller
  Cc: David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
	Simon Horman, linux-x25, netdev, linux-kernel, lvc-project

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>
---
 net/x25/af_x25.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index f7a7c7798c3b..d18d51412cc0 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;
-- 
2.39.2

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