CVE-2024-35882

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

SUNRPC: Fix a slow server-side memory leak with RPC-over-TCP

Jan Schunk reports that his small NFS servers suffer from memory

exhaustion after just a few days. A bisect shows that commit

e18e157bb5c8 ("SUNRPC: Send RPC message on TCP with a single

sock_sendmsg() call") is the first bad commit.

That commit assumed that sock_sendmsg() releases all the pages in

the underlying bio_vec array, but the reality is that it doesn't.

svc_xprt_release() releases the rqst's response pages, but the

record marker page fragment isn't one of those, so it is never

released.

This is a narrow fix that can be applied to stable kernels. A

more extensive fix is in the works.