@@ -82,6 +82,8 @@
#define WRITE_BUF_SIZE 8192 /* TX only */
#define GS_CONSOLE_BUF_SIZE 8192
+static DEFINE_SPINLOCK(serial_port_lock);
+
/* console info */
struct gs_console {
struct console console;
@@ -1370,13 +1372,15 @@ EXPORT_SYMBOL_GPL(gserial_connect);
void gserial_disconnect(struct gserial *gser)
{
struct gs_port *port = gser->ioport;
- unsigned long flags;
+ unsigned long flags;
if (!port)
return;
+ spin_lock_irqsave(&serial_port_lock, flags);
+
/* tell the TTY glue not to do I/O here any more */
- spin_lock_irqsave(&port->port_lock, flags);
+ spin_lock(&port->port_lock);
gs_console_disconnect(port);
@@ -1391,7 +1395,8 @@ void gserial_disconnect(struct gserial *gser)
tty_hangup(port->port.tty);
}
port->suspended = false;
- spin_unlock_irqrestore(&port->port_lock, flags);
+ spin_unlock(&port->port_lock);
+ spin_unlock_irqrestore(&serial_port_lock, flags);
/* disable endpoints, aborting down any active I/O */
usb_ep_disable(gser->out);
@@ -1426,9 +1431,16 @@ EXPORT_SYMBOL_GPL(gserial_suspend);
void gserial_resume(struct gserial *gser)
{
struct gs_port *port = gser->ioport;
- unsigned long flags;
+ unsigned long flags;
- spin_lock_irqsave(&port->port_lock, flags);
+ spin_lock_irqsave(&serial_port_lock, flags);
+ if (!port) {
+ spin_unlock_irqrestore(&serial_port_lock, flags);
+ return;
+ }
+
+ spin_lock(&port->port_lock);
+ spin_unlock(&serial_port_lock);
port->suspended = false;
if (!port->start_delayed) {
spin_unlock_irqrestore(&port->port_lock, flags);
Consider a case where gserial_disconnect has already cleared gser->ioport. And if a wakeup interrupt triggers afterwards, gserial_resume gets called, which will lead to accessing of gser->ioport and thus causing null pointer dereference.Add a null pointer check to prevent this. Added a static spinlock to prevent gser->ioport from becoming null after the newly added check. Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume callbacks") Signed-off-by: Prashanth K <quic_prashk@quicinc.com> --- v3: Fixed the spin_lock_irqsave flags. drivers/usb/gadget/function/u_serial.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)