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.

Affected Software

References

• https://git.kernel.org/stable/c/33930840b5f0a79f826e7c69dc6cd78f72a67481
• https://git.kernel.org/stable/c/589f761236e05ff9de1bdfd6a5258f113e6457fe
• https://git.kernel.org/stable/c/d8f0b83753809761a560c4b33249388548ba6e43
• https://git.kernel.org/stable/c/da652cb17f9faeea1fa44b7215e8869a0b10b664
• https://git.kernel.org/stable/c/ed80d009b154aa204f541d390884851b3d4f15ae