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authorDan Rosenberg <drosenberg@vsecurity.com>2011-06-24 08:38:05 -0400
committerGustavo F. Padovan <padovan@profusion.mobi>2011-06-28 14:57:55 -0300
commit7ac28817536797fd40e9646452183606f9e17f71 (patch)
tree0e8f9966e42128fea6a49436055570f8575d34a9
parentfa7ccfb17033bfb5bca86f6b909cab0b807efbc0 (diff)
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Bluetooth: Prevent buffer overflow in l2cap config request
A remote user can provide a small value for the command size field in the command header of an l2cap configuration request, resulting in an integer underflow when subtracting the size of the configuration request header. This results in copying a very large amount of data via memcpy() and destroying the kernel heap. Check for underflow. Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Cc: stable <stable@kernel.org> Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
-rw-r--r--net/bluetooth/l2cap_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 56fdd9162da9..7d8a66b04f50 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2334,7 +2334,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
/* Reject if config buffer is too small. */
len = cmd_len - sizeof(*req);
- if (chan->conf_len + len > sizeof(chan->conf_req)) {
+ if (len < 0 || chan->conf_len + len > sizeof(chan->conf_req)) {
l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
l2cap_build_conf_rsp(chan, rsp,
L2CAP_CONF_REJECT, flags), rsp);