diff options
| author | Marcel Holtmann <marcel@holtmann.org> | 2007-01-04 22:57:52 +0100 |
|---|---|---|
| committer | Adrian Bunk <bunk@stusta.de> | 2007-01-09 03:23:30 +0100 |
| commit | 044a3e96c42df125bbc046495d49a6b8f380aa5a (patch) | |
| tree | d492388f69a501d41b50c7fc92c14b0efa85158f | |
| parent | d9be428145481c9c23e02e25a49205fc9def5d36 (diff) | |
| download | lwn-044a3e96c42df125bbc046495d49a6b8f380aa5a.tar.gz lwn-044a3e96c42df125bbc046495d49a6b8f380aa5a.zip | |
Bluetooth: Add packet size checks for CAPI messages (CVE-2006-6106)
With malformed packets it might be possible to overwrite internal
CMTP and CAPI data structures. This patch adds additional length
checks to prevent these kinds of remote attacks.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
| -rw-r--r-- | net/bluetooth/cmtp/capi.c | 39 |
1 files changed, 33 insertions, 6 deletions
diff --git a/net/bluetooth/cmtp/capi.c b/net/bluetooth/cmtp/capi.c index b2e7e38531c6..18910ffa99cd 100644 --- a/net/bluetooth/cmtp/capi.c +++ b/net/bluetooth/cmtp/capi.c @@ -199,6 +199,9 @@ static void cmtp_recv_interopmsg(struct cmtp_session *session, struct sk_buff *s switch (CAPIMSG_SUBCOMMAND(skb->data)) { case CAPI_CONF: + if (skb->len < CAPI_MSG_BASELEN + 10) + break; + func = CAPIMSG_U16(skb->data, CAPI_MSG_BASELEN + 5); info = CAPIMSG_U16(skb->data, CAPI_MSG_BASELEN + 8); @@ -229,6 +232,9 @@ static void cmtp_recv_interopmsg(struct cmtp_session *session, struct sk_buff *s break; case CAPI_FUNCTION_GET_PROFILE: + if (skb->len < CAPI_MSG_BASELEN + 11 + sizeof(capi_profile)) + break; + controller = CAPIMSG_U16(skb->data, CAPI_MSG_BASELEN + 11); msgnum = CAPIMSG_MSGID(skb->data); @@ -249,17 +255,26 @@ static void cmtp_recv_interopmsg(struct cmtp_session *session, struct sk_buff *s break; case CAPI_FUNCTION_GET_MANUFACTURER: + if (skb->len < CAPI_MSG_BASELEN + 15) + break; + controller = CAPIMSG_U32(skb->data, CAPI_MSG_BASELEN + 10); if (!info && ctrl) { + int len = min_t(uint, CAPI_MANUFACTURER_LEN, + skb->data[CAPI_MSG_BASELEN + 14]); + + memset(ctrl->manu, 0, CAPI_MANUFACTURER_LEN); strncpy(ctrl->manu, - skb->data + CAPI_MSG_BASELEN + 15, - skb->data[CAPI_MSG_BASELEN + 14]); + skb->data + CAPI_MSG_BASELEN + 15, len); } break; case CAPI_FUNCTION_GET_VERSION: + if (skb->len < CAPI_MSG_BASELEN + 32) + break; + controller = CAPIMSG_U32(skb->data, CAPI_MSG_BASELEN + 12); if (!info && ctrl) { @@ -272,13 +287,18 @@ static void cmtp_recv_interopmsg(struct cmtp_session *session, struct sk_buff *s break; case CAPI_FUNCTION_GET_SERIAL_NUMBER: + if (skb->len < CAPI_MSG_BASELEN + 17) + break; + controller = CAPIMSG_U32(skb->data, CAPI_MSG_BASELEN + 12); if (!info && ctrl) { + int len = min_t(uint, CAPI_SERIAL_LEN, + skb->data[CAPI_MSG_BASELEN + 16]); + memset(ctrl->serial, 0, CAPI_SERIAL_LEN); strncpy(ctrl->serial, - skb->data + CAPI_MSG_BASELEN + 17, - skb->data[CAPI_MSG_BASELEN + 16]); + skb->data + CAPI_MSG_BASELEN + 17, len); } break; @@ -287,14 +307,18 @@ static void cmtp_recv_interopmsg(struct cmtp_session *session, struct sk_buff *s break; case CAPI_IND: + if (skb->len < CAPI_MSG_BASELEN + 6) + break; + func = CAPIMSG_U16(skb->data, CAPI_MSG_BASELEN + 3); if (func == CAPI_FUNCTION_LOOPBACK) { + int len = min_t(uint, skb->len - CAPI_MSG_BASELEN - 6, + skb->data[CAPI_MSG_BASELEN + 5]); appl = CAPIMSG_APPID(skb->data); msgnum = CAPIMSG_MSGID(skb->data); cmtp_send_interopmsg(session, CAPI_RESP, appl, msgnum, func, - skb->data + CAPI_MSG_BASELEN + 6, - skb->data[CAPI_MSG_BASELEN + 5]); + skb->data + CAPI_MSG_BASELEN + 6, len); } break; @@ -312,6 +336,9 @@ void cmtp_recv_capimsg(struct cmtp_session *session, struct sk_buff *skb) BT_DBG("session %p skb %p len %d", session, skb, skb->len); + if (skb->len < CAPI_MSG_BASELEN) + return; + if (CAPIMSG_COMMAND(skb->data) == CAPI_INTEROPERABILITY) { cmtp_recv_interopmsg(session, skb); return; |