usb: typec: fix dereference before null check on adev

Pointer adev is being dereferenced before it is being sanity
checked with a null pointer check, hence it is possible for
a null pointer dereference to occur.  Fix this by dereferencing
adev only once it is null checked.

Detected by CoverityScan, CID#1471598 ("Dereference before null check")

Fixes: 8a37d87d72f0 ("usb: typec: Bus type for alternate modes")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c
index 999d7904172ad91daae6f5bd21636a98bd90b168..95a2b10127db564607dfbb9f7a529a6719fd0e31 100644 (file)
--- a/drivers/usb/typec/bus.c
+++ b/drivers/usb/typec/bus.c
@@ -51,7 +51,7 @@ static int typec_altmode_set_state(struct typec_altmode *adev, int state)
 int typec_altmode_notify(struct typec_altmode *adev,
                         unsigned long conf, void *data)
 {
-       bool is_port = is_typec_port(adev->dev.parent);
+       bool is_port;
        struct altmode *altmode;
        struct altmode *partner;
        int ret;
@@ -64,6 +64,7 @@ int typec_altmode_notify(struct typec_altmode *adev,
        if (!altmode->partner)
                return -ENODEV;
 
+       is_port = is_typec_port(adev->dev.parent);
        partner = altmode->partner;
 
        ret = typec_altmode_set_mux(is_port ? altmode : partner, (u8)conf);