On 1/10/2024 2:52 PM, Sergei Shtylyov wrote:
On 1/10/24 12:14 PM, Udipto Goswami wrote:
Currently,the function update_port_device_state gets the usb_hub from
Need space between comma and "the"...
got it.
udev->parent by calling usb_hub_to_struct_hub.
However, in case the actconfig or the maxchild is 0, the usb_hub would
be NULL and upon further accessing to get port_dev would result in null
pointer dereference.
Fix this by introducing an if check after the usb_hub is populated.
Fixes: 83cb2604f641 ("usb: core: add sysfs entry for usb device state")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Udipto Goswami <quic_ugoswami@xxxxxxxxxxx>
[...]
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index ffd7c99e24a3..5ba1875e6bf4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2053,9 +2053,22 @@ static void update_port_device_state(struct usb_device *udev)
if (udev->parent) {
hub = usb_hub_to_struct_hub(udev->parent);
- port_dev = hub->ports[udev->portnum - 1];
- WRITE_ONCE(port_dev->state, udev->state);
- sysfs_notify_dirent(port_dev->state_kn);
+
+ /*
+ * The Link Layer Validation System Driver (lvstest)
+ * has step to unbind the hub before running the rest
+ * of the procedure. This triggers hub_disconnect which
+ * will set the hub's maxchild to 0, further resulting
Resulting in.
got it.
+ * usb_hub_to_struct_hub returning NULL.
+ *
+ * Add if check to avoid running into NULL pointer
+ * de-reference.
This is obvious from the code below, I think...
ok will remove this.
Thanks,
-Udipto
