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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Dan Carpenter <dan.carpenter@oracle.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0425/1039] ax25: uninitialized variable in ax25_setsockopt()
Date:   Mon, 24 Jan 2022 19:36:54 +0100
Message-Id: <20220124184139.589701660@linuxfoundation.org>
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From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 9371937092d5fd502032c1bb4475b36b39b1f1b3 ]

The "opt" variable is unsigned long but we only copy 4 bytes from
the user so the lower 4 bytes are uninitialized.

I have changed the integer overflow checks from ULONG to UINT as well.
This is a slight API change but I don't expect it to break anything.

Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ax25/af_ax25.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index cfca99e295b80..02f43f3e2c564 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -536,7 +536,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 	ax25_cb *ax25;
 	struct net_device *dev;
 	char devname[IFNAMSIZ];
-	unsigned long opt;
+	unsigned int opt;
 	int res = 0;
 
 	if (level != SOL_AX25)
@@ -568,7 +568,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T1:
-		if (opt < 1 || opt > ULONG_MAX / HZ) {
+		if (opt < 1 || opt > UINT_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -577,7 +577,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T2:
-		if (opt < 1 || opt > ULONG_MAX / HZ) {
+		if (opt < 1 || opt > UINT_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -593,7 +593,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_T3:
-		if (opt < 1 || opt > ULONG_MAX / HZ) {
+		if (opt < 1 || opt > UINT_MAX / HZ) {
 			res = -EINVAL;
 			break;
 		}
@@ -601,7 +601,7 @@ static int ax25_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case AX25_IDLE:
-		if (opt > ULONG_MAX / (60 * HZ)) {
+		if (opt > UINT_MAX / (60 * HZ)) {
 			res = -EINVAL;
 			break;
 		}
-- 
2.34.1