[PATCH][next] usb: typec: fix dereference before null check on adev

From: Colin King
Date: Wed Jul 04 2018 - 08:34:14 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
drivers/usb/typec/bus.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c
index 999d7904172a..95a2b10127db 100644
--- 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);
--
2.17.1