CVE-2022-50046

In the Linux kernel, the following vulnerability has been resolved:

net/sunrpc: fix potential memory leaks in rpcsysfsxprtstatechange()

The issue happens on some error handling paths. When the function fails to grab the object xprt, it simply returns 0, forgetting to decrease the reference count of another object xps, which is increased by rpcsysfsxprtkobjgetxprtswitch(), causing refcount leaks. Also, the function forgets to check whether xps is valid before using it, which may result in NULL-dereferencing issues.

Fix it by adding proper error handling code when either xprt or xps is NULL.