Commit 51eda36d authored by Luiz Augusto von Dentz's avatar Luiz Augusto von Dentz
Browse files

Bluetooth: SCO: Fix not validating setsockopt user input 



syzbot reported sco_sock_setsockopt() is copying data without
checking user input length.

BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset
include/linux/sockptr.h:49 [inline]
BUG: KASAN: slab-out-of-bounds in copy_from_sockptr
include/linux/sockptr.h:55 [inline]
BUG: KASAN: slab-out-of-bounds in sco_sock_setsockopt+0xc0b/0xf90
net/bluetooth/sco.c:893
Read of size 4 at addr ffff88805f7b15a3 by task syz-executor.5/12578

Fixes: ad10b1a4 ("Bluetooth: Add Bluetooth socket voice option")
Fixes: b96e9c67 ("Bluetooth: Add BT_DEFER_SETUP option to sco socket")
Fixes: 00398e1d ("Bluetooth: Add support for BT_PKT_STATUS CMSG data for SCO connections")
Fixes: f6873401 ("Bluetooth: Allow setting of codec for HFP offload use case")
Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
parent 45d355a9

include/net/bluetooth/bluetooth.h

+9 −0
Original line number Diff line number Diff line
@@ -585,6 +585,15 @@ static inline struct sk_buff *bt_skb_sendmmsg(struct sock *sk, 
	return skb;

}



static inline int bt_copy_from_sockptr(void *dst, size_t dst_size,

				       sockptr_t src, size_t src_size)

{

	if (dst_size > src_size)

		return -EINVAL;



	return copy_from_sockptr(dst, src, dst_size);

}



int bt_to_errno(u16 code);

__u8 bt_status(int err);

net/bluetooth/sco.c

+10 −13
Original line number Diff line number Diff line
@@ -824,7 +824,7 @@ static int sco_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_voice voice;

	u32 opt;

	struct bt_codecs *codecs;
@@ -843,10 +843,9 @@ static int sco_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);
@@ -863,11 +862,10 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname, 


		voice.setting = sco_pi(sk)->setting;



		len = min_t(unsigned int, sizeof(voice), optlen);

		if (copy_from_sockptr(&voice, optval, len)) {

			err = -EFAULT;

		err = bt_copy_from_sockptr(&voice, sizeof(voice), optval,

					   optlen);

		if (err)

			break;

		}



		/* Explicitly check for these values */

		if (voice.setting != BT_VOICE_TRANSPARENT &&
@@ -890,10 +888,9 @@ static int sco_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);
@@ -934,9 +931,9 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname, 
			break;

		}



		if (copy_from_sockptr(buffer, optval, optlen)) {

		err = bt_copy_from_sockptr(buffer, optlen, optval, optlen);

		if (err) {

			hci_dev_put(hdev);

			err = -EFAULT;

			break;

		}