CVE-2026-90235

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

sunrpc: xprtsock: annotate shared socket callbacks with READONCE/WRITEONCE

xprtsock replaces and restores sk->skdataready and

sk->skwritespace on live sockets with plain stores, and

xsudpdosetbuffersize() invokes sk->skwrite_space via a plain

load. These callback pointers are shared with generic socket and

protocol paths that may read or invoke them concurrently, so xprtsock

needs the same READONCE()/WRITEONCE() callback visibility contract

that the validated 4022 family applied elsewhere.

When SUNRPC takes over an AF_LOCAL, UDP, or TCP socket and later

restores the lower-socket callbacks during teardown, another CPU may

still hold an earlier callback snapshot. The plain replace/restore

pattern leaves the same visibility hole as the validated 4022 family,

so a stale snapshot can still invoke xsdataready() or

xsudpwrite_space() after the live callback fields have already been

restored to the lower-socket handlers.

Use WRITEONCE() for the shared skdataready and skwrite_space

stores in xslocalfinishconnecting(), xsudpfinishconnecting(),

xstcpfinishconnecting(), and xsrestoreoldcallbacks(). Use

READONCE() for the direct skwrite_space invocation in

xsudpdosetbuffer_size(). This matches the required callback

visibility contract while leaving adjacent skstatechange and

skerrorreport handling unchanged.