ttyprintk: Fix NULL pointer deref by setting tty_port ops after initializing port
tty_port_init() zeroes out the tty port, which means that we have to set the
ops pointer /after/, not before this call. Otherwise, tty_port_open will crash
when it tries to deref ops, which is now a NULL pointer.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c
index 4945bd3..d5d2e4a 100644
--- a/drivers/char/ttyprintk.c
+++ b/drivers/char/ttyprintk.c
@@ -179,7 +179,6 @@
{
int ret = -ENOMEM;
- tpk_port.port.ops = &null_ops;
mutex_init(&tpk_port.port_write_mutex);
ttyprintk_driver = tty_alloc_driver(1,
@@ -190,6 +189,7 @@
return PTR_ERR(ttyprintk_driver);
tty_port_init(&tpk_port.port);
+ tpk_port.port.ops = &null_ops;
ttyprintk_driver->driver_name = "ttyprintk";
ttyprintk_driver->name = "ttyprintk";