usb: typec: mux: Fix matching with typec_altmode_desc

stable inclusion
from stable-5.10.42
commit 77c6f2b36de1ae5742a1ad20cd5911849ed085f7
bugzilla: 55093
CVE: NA

--------------------------------

commit acf5631c upstream.

In typec_mux_match() "nval" is assigned the number of elements in the
"svid" fwnode property, then the variable is used to store the success
of the read and finally attempts to loop between 0 and "success" - i.e.
not at all - and the code returns indicating that no match was found.

Fix this by using a separate variable to track the success of the read,
to allow the loop to get a change to find a match.

Fixes: 96a6d031 ("usb: typec: mux: Find the muxes by also matching against the device node")
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210516034730.621461-1-bjorn.andersson@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/usb/typec/mux.c

@@ -191,6 +191,7 @@ static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id,
 	bool match;
 	int nval;
 	u16 *val;
+	int ret;
 	int i;
 
 	/*
@@ -218,10 +219,10 @@ static void *typec_mux_match(struct fwnode_handle *fwnode, const char *id,
 	if (!val)
 		return ERR_PTR(-ENOMEM);
 
-	nval = fwnode_property_read_u16_array(fwnode, "svid", val, nval);
-	if (nval < 0) {
+	ret = fwnode_property_read_u16_array(fwnode, "svid", val, nval);
+	if (ret < 0) {
 		kfree(val);
-		return ERR_PTR(nval);
+		return ERR_PTR(ret);
 	}
 
 	for (i = 0; i < nval; i++) {