diff options
| author | Kuen-Han Tsai <khtsai@google.com> | 2023-06-02 15:00:06 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-06-13 11:55:09 +0200 |
| commit | ffd603f214237e250271162a5b325c6199a65382 (patch) | |
| tree | 8fc707c8dccfecaed01e094af1e5a3ed6c85dc8e | |
| parent | 0a453dc9f260281e3a063e07b526a7e494e496fe (diff) | |
usb: gadget: u_serial: Add null pointer check in gs_start_io
If gs_close has cleared port->port.tty and gs_start_io is called
afterwards, then the function tty_wakeup will attempt to access the value
of the pointer port->port.tty which will cause a null pointer
dereference error.
To avoid this, add a null pointer check to gs_start_io before attempting
to access the value of the pointer port->port.tty.
Signed-off-by: Kuen-Han Tsai <khtsai@google.com>
Message-ID: <20230602070009.1353946-1-khtsai@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/gadget/function/u_serial.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 97f07757d19e..1115396b46a0 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -539,16 +539,20 @@ static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head, static int gs_start_io(struct gs_port *port) { struct list_head *head = &port->read_pool; - struct usb_ep *ep = port->port_usb->out; + struct usb_ep *ep; int status; unsigned started; + if (!port->port_usb || !port->port.tty) + return -EIO; + /* Allocate RX and TX I/O buffers. We can't easily do this much * earlier (with GFP_KERNEL) because the requests are coupled to * endpoints, as are the packet sizes we'll be using. Different * configurations may use different endpoints with a given port; * and high speed vs full speed changes packet sizes too. */ + ep = port->port_usb->out; status = gs_alloc_requests(ep, head, gs_read_complete, &port->read_allocated); if (status) |