During enumeration or composition switch,a userspace process
agnostic of the conventions of configs can try to create function
symlinks even after the UDC is bound to current config which is
not correct. Potentially it can create duplicates within the
current config.
Prevent this by adding a check if udc_name already exists then bail
out of cfg_link.
Fixes: 88af8bbe4ef7 ("usb: gadget: the start of the configfs interface")
Signed-off-by: Udipto Goswami <quic_ugoswami@xxxxxxxxxxx>
---
v2: Fixed spelling mistakes in commit text.
drivers/usb/gadget/configfs.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 78e7353e397b..434e49d29c50 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -455,6 +455,11 @@ static int config_usb_cfg_link(
}
}
+ if (gi->composite.gadget_driver.udc_name) {
+ ret = -EINVAL;
+ goto out;
+ }
+
f = usb_get_function(fi);
if (IS_ERR(f)) {
ret = PTR_ERR(f);
--
2.17.1
