On 22-05-23 07:51 am, Chunfeng Yun wrote:
When gserial_disconnect has already cleared gser->ioport, and the
suspend triggers afterwards, gserial_suspend gets called, which will
lead to accessing of gser->ioport and thus causing null pointer
dereference. Add a null pointer check to prevent it as the bellow
patch does:
5ec63fdbca60 ("usb: gadget: u_serial: Add null pointer check in gserial_resume")
Fixes: aba3a8d01d62 ("usb: gadget: u_serial: add suspend resume callbacks")
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/gadget/function/u_serial.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index a0ca47fbff0f..40ba220cf6d2 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -1420,10 +1420,18 @@ EXPORT_SYMBOL_GPL(gserial_disconnect);
void gserial_suspend(struct gserial *gser)
{
- struct gs_port *port = gser->ioport;
+ struct gs_port *port;
unsigned long flags;
- spin_lock_irqsave(&port->port_lock, flags);
+ spin_lock_irqsave(&serial_port_lock, flags);
+ port = gser->ioport;
+ if (!port) {
+ spin_unlock_irqrestore(&serial_port_lock, flags);
+ return;
+ }
+
+ spin_lock(&port->port_lock);
+ spin_unlock(&serial_port_lock);
port->suspended = true;
spin_unlock_irqrestore(&port->port_lock, flags);
}
Hi Chunfeng,
This looks same as the following patch.
https://lore.kernel.org/linux-usb/1683278317-11774-1-git-send-email-quic_prashk@xxxxxxxxxxx/
Regards
