On Tue, 24 Aug 2010, Mat Martineau wrote:
Valid L2CAP PSMs are odd numbers, and the least significant bit of the
most significant byte must be 0.
Signed-off-by: Mat Martineau <mathewm@xxxxxxxxxxxxxx>
---
net/bluetooth/l2cap.c | 24 ++++++++++++++++++++----
1 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index c784703..1f1fa3c 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1008,10 +1008,20 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
goto done;
}
- if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
- !capable(CAP_NET_BIND_SERVICE)) {
- err = -EACCES;
- goto done;
+ if (la.l2_psm) {
+ __u16 psm = __le16_to_cpu(la.l2_psm);
+
+ /* PSM must be odd and lsb of upper byte must be 0 */
+ if ((psm & 0x0101) != 0x0001) {
+ err = -EINVAL;
+ goto done;
+ }
+
+ /* Restrict usage of well-known PSMs */
+ if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE)) {
+ err = -EACCES;
+ goto done;
+ }
}
write_lock_bh(&l2cap_sk_list.lock);
@@ -1190,6 +1200,12 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
goto done;
}
+ /* PSM must be odd and lsb of upper byte must be 0 */
+ if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001) {
+ err = -EINVAL;
+ goto done;
+ }
+
/* Set destination address and psm */
bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr);
l2cap_pi(sk)->psm = la.l2_psm;
This patch should not be merged - PSM 0 needs to be allowed when
connecting to SOCK_RAW sockets, so bonding works right.
--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
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