mei: protect mei_cl_mtu from null dereference
A receive callback is queued while the client is still connected
but can still be called after the client was disconnected. Upon
disconnect cl->me_cl is set to NULL, hence we need to check
that ME client is not-NULL in mei_cl_mtu to avoid
null dereference.
Cc: <[email protected]>
Signed-off-by: Alexander Usyskin <[email protected]>
Signed-off-by: Tomas Winkler <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h
index 64143d4..9e08a98 100644
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -182,11 +182,11 @@ static inline u8 mei_cl_me_id(const struct mei_cl *cl)
*
* @cl: host client
*
- * Return: mtu
+ * Return: mtu or 0 if client is not connected
*/
static inline size_t mei_cl_mtu(const struct mei_cl *cl)
{
- return cl->me_cl->props.max_msg_length;
+ return cl->me_cl ? cl->me_cl->props.max_msg_length : 0;
}
/**
