[PATCH v2 4/5] Bluetooth: ISO: Fix not validating setsockopt user input

[Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>]

From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>

Check user input length before copying data.

Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type")
Fixes: 0731c5ab4d51 ("Bluetooth: ISO: Add support for BT_PKT_STATUS")
Fixes: f764a6c2c1e4 ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
 net/bluetooth/iso.c | 36 ++++++++++++------------------------
 1 file changed, 12 insertions(+), 24 deletions(-)

diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index 0dda77e2e52c..5964e2e87829 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -1499,7 +1499,7 @@ static int iso_sock_setsockopt(struct socket *sock, int level, int optname,
 			       sockptr_t optval, unsigned int optlen)
 {
 	struct sock *sk = sock->sk;
-	int len, err = 0;
+	int err = 0;
 	struct bt_iso_qos qos = default_qos;
 	u32 opt;
 
@@ -1514,10 +1514,9 @@ static int iso_sock_setsockopt(struct socket *sock, int level, int optname,
 			break;
 		}
 
-		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen);
+		if (err)
 			break;
-		}
 
 		if (opt)
 			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
@@ -1526,10 +1525,9 @@ static int iso_sock_setsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case BT_PKT_STATUS:
-		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen);
+		if (err)
 			break;
-		}
 
 		if (opt)
 			set_bit(BT_SK_PKT_STATUS, &bt_sk(sk)->flags);
@@ -1546,17 +1544,9 @@ static int iso_sock_setsockopt(struct socket *sock, int level, int optname,
 			break;
 		}
 
-		len = min_t(unsigned int, sizeof(qos), optlen);
-
-		if (copy_from_sockptr(&qos, optval, len)) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&qos, sizeof(qos), optval, optlen);
+		if (err)
 			break;
-		}
-
-		if (len == sizeof(qos.ucast) && !check_ucast_qos(&qos)) {
-			err = -EINVAL;
-			break;
-		}
 
 		iso_pi(sk)->qos = qos;
 		iso_pi(sk)->qos_user_set = true;
@@ -1571,18 +1561,16 @@ static int iso_sock_setsockopt(struct socket *sock, int level, int optname,
 		}
 
 		if (optlen > sizeof(iso_pi(sk)->base)) {
-			err = -EOVERFLOW;
+			err = -EINVAL;
 			break;
 		}
 
-		len = min_t(unsigned int, sizeof(iso_pi(sk)->base), optlen);
-
-		if (copy_from_sockptr(iso_pi(sk)->base, optval, len)) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(iso_pi(sk)->base, optlen, optval,
+					   optlen);
+		if (err)
 			break;
-		}
 
-		iso_pi(sk)->base_len = len;
+		iso_pi(sk)->base_len = optlen;
 
 		break;
 
-- 
2.44.0