[34-longterm 240/247] Bluetooth: bnep: fix buffer overflow

[Paul Gortmaker]

From: Vasiliy Kulikov <segoon@xxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    If you see a problem with using this for longterm, please comment.
                   -------------------

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@xxxxxxxxxxxx>
Signed-off-by: Gustavo F. Padovan <padovan@xxxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 net/bluetooth/bnep/sock.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/net/bluetooth/bnep/sock.c b/net/bluetooth/bnep/sock.c
index 2862f53..d935da7 100644
--- 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) {
-- 
1.7.4.4

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