Re: [PATCH net-next 2/2] net: annotate lockless writes to sk->sk_err
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From: Eric Dumazet <edumazet@kernel.org>
Date: 2026-10-02 08:51:10
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On Fri, Oct 2, 2026 at 9:29 AM Quanye Yang via B4 Relay [off-list ref] wrote:
From: Quanye Yang <redacted> do_recvmmsg() and getsockopt(SO_ERROR) clear sk_err with xchg() without the socket lock. TCP, MPTCP and kTLS already peek the same field with READ_ONCE() or consume it via sock_error(). sock_dequeue_err_skb() still uses plain stores. tcp_recvmsg() can call it via MSG_ERRQUEUE before lock_sock(), so those writes race with the annotated readers and with sock_error(). The same unmarked stores exist in strp_abort_strp() and sk_psock_report_error(), which run on the TCP/TLS socket. Annotate those writers with WRITE_ONCE(). No extra ordering is needed; this does not change who wins when ICMP error-queue entries overwrite sk_err. Link: https://lore.kernel.org/netdev/3d9d442f-f168-43da-87b0-010ad5a78365@redhat.com/ (local) Signed-off-by: Quanye Yang <redacted>
Reviewed-by: Eric Dumazet <edumazet@kernel.org>