CVE-2026-90235

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

sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE

xprtsock replaces and restores sk->sk_data_ready and

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

xs_udp_do_set_buffer_size() invokes sk->sk_write_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 READ_ONCE()/WRITE_ONCE() 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 xs_data_ready() or

xs_udp_write_space() after the live callback fields have already been

restored to the lower-socket handlers.

Use WRITE_ONCE() for the shared sk_data_ready and sk_write_space

stores in xs_local_finish_connecting(), xs_udp_finish_connecting(),

xs_tcp_finish_connecting(), and xs_restore_old_callbacks(). Use

READ_ONCE() for the direct sk_write_space invocation in

xs_udp_do_set_buffer_size(). This matches the required callback

visibility contract while leaving adjacent sk_state_change and

sk_error_report handling unchanged.