Bluetooth: hidp: fix buffer overflow

Yoha-test · holtmann · commit a1616a5ac99e · 2019-04-23T19:04:38.000+02:00
Struct ca is copied from userspace. It is not checked whether the "name" field is NULL terminated, which allows local users to obtain potentially sensitive information from kernel stack memory, via a HIDPCONNADD command. This vulnerability is similar to CVE-2011-1079. Signed-off-by: Young Xiao <YangX92@hotmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Cc: stable@vger.kernel.org
diff --git a/net/bluetooth/hidp/sock.c b/net/bluetooth/hidp/sock.c
@@ -75,6 +75,7 @@ static int do_hidp_sock_ioctl(struct socket *sock, unsigned int cmd, void __user
 			sockfd_put(csock);
 			return err;
 		}
+		ca.name[sizeof(ca.name)-1] = 0;
 
 		err = hidp_connection_add(&ca, csock, isock);
 		if (!err && copy_to_user(argp, &ca, sizeof(ca)))

Original file line number	Diff line number	Diff line change
`@@ -75,6 +75,7 @@ static int do_hidp_sock_ioctl(struct socket *sock, unsigned int cmd, void __user`
`75`	`75`	`sockfd_put(csock);`
`76`	`76`	`return err;`
`77`	`77`	`}`
	`78`	`+ ca.name[sizeof(ca.name)-1] = 0;`
`78`	`79`
`79`	`80`	`err = hidp_connection_add(&ca, csock, isock);`
`80`	`81`	`if (!err && copy_to_user(argp, &ca, sizeof(ca)))`