[PATCH v2 5/5] Bluetooth: hci_sock: 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: 09572fca7223 ("Bluetooth: hci_sock: Add support for BT_{SND,RCV}BUF")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
 net/bluetooth/hci_sock.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 4ee1b976678b..703b84bd48d5 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1946,10 +1946,9 @@ static int hci_sock_setsockopt_old(struct socket *sock, int level, int optname,
 
 	switch (optname) {
 	case HCI_DATA_DIR:
-		if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, len);
+		if (err)
 			break;
-		}
 
 		if (opt)
 			hci_pi(sk)->cmsg_mask |= HCI_CMSG_DIR;
@@ -1958,10 +1957,9 @@ static int hci_sock_setsockopt_old(struct socket *sock, int level, int optname,
 		break;
 
 	case HCI_TIME_STAMP:
-		if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, len);
+		if (err)
 			break;
-		}
 
 		if (opt)
 			hci_pi(sk)->cmsg_mask |= HCI_CMSG_TSTAMP;
@@ -1979,11 +1977,9 @@ static int hci_sock_setsockopt_old(struct socket *sock, int level, int optname,
 			uf.event_mask[1] = *((u32 *) f->event_mask + 1);
 		}
 
-		len = min_t(unsigned int, len, sizeof(uf));
-		if (copy_from_sockptr(&uf, optval, len)) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&uf, sizeof(uf), optval, len);
+		if (err)
 			break;
-		}
 
 		if (!capable(CAP_NET_RAW)) {
 			uf.type_mask &= hci_sec_filter.type_mask;
@@ -2042,10 +2038,9 @@ static int hci_sock_setsockopt(struct socket *sock, int level, int optname,
 			goto done;
 		}
 
-		if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
-			err = -EFAULT;
+		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, len);
+		if (err)
 			break;
-		}
 
 		hci_pi(sk)->mtu = opt;
 		break;
-- 
2.44.0