Bluetooth: bnep: fix buffer overflow

commit 43629f8f5ea32a998d06d1bb41eefa0e821ff573 upstream.

Struct ca is copied from userspace.  It is not checked whether the "device"
field is NULL terminated.  This potentially leads to BUG() inside of
alloc_netdev_mqs() and/or information leak by creating a device with a name
made of contents of kernel stack.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/bluetooth/bnep/sock.c b/net/bluetooth/bnep/sock.c
index e857628b0b27e61234102dc843ab0cc84a5f5c42..efc85dc9d8c34c886adbfa6ebe111c1658b6c604 100644 (file)
--- a/net/bluetooth/bnep/sock.c
+++ b/net/bluetooth/bnep/sock.c
@@ -88,6 +88,7 @@ static int bnep_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long
                        sockfd_put(nsock);
                        return -EBADFD;
                }
+               ca.device[sizeof(ca.device)-1] = 0;
 
                err = bnep_add_connection(&ca, nsock);
                if (!err) {