Bluetooth: bnep: fix buffer overflow

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 <[email protected]>
Signed-off-by: Gustavo F. Padovan <[email protected]>

diff --git a/net/bluetooth/bnep/sock.c b/net/bluetooth/bnep/sock.c
index 2862f53b66b15b8b680322b32c5196f502adc7f0..d935da71ab3b57ff7c46962f339b257f39e57952 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) {