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>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

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) {