In the Linux kernel, the following vulnerability has been resolved: SUNRPC: lock against ->sock changing during sysfs read ->sock can be set to NULL asynchronously unless ->recv_mutex is held. So it is important to hold that mutex. Otherwise a sysfs read can trigger an oops. Commit 17f09d3f619a ("SUNRPC: Check if the xprt is connected before handling sysfs reads") appears to attempt to fix this problem, but it only narrows the race window.
https://git.kernel.org/stable/c/b49ea673e119f59c71645e2f65b3ccad857c90ee
https://git.kernel.org/stable/c/9482ab4540f5bcc869b44c067ae99b5fca16bd07