sockmap performs lockless writes to sk->sk_prot on the following paths:
tcp_bpf_{recvmsg|sendmsg} / sock_map_unref
sk_psock_put
sk_psock_drop
sk_psock_restore_proto
WRITE_ONCE(sk->sk_prot, proto)
To prevent load/store tearing [1], and to make tooling aware of intentional
shared access [2], we need to annotate other sites that access sk_prot with
READ_ONCE/WRITE_ONCE macros.
Change done with Coccinelle with following semantic patch:
@@
expression E;
identifier I;
struct sock *sk;
identifier sk_prot =~ "^sk_prot$";
@@
(
E =
-sk->sk_prot
+READ_ONCE(sk->sk_prot)
|
-sk->sk_prot = E
+WRITE_ONCE(sk->sk_prot, E)
|
-sk->sk_prot
+READ_ONCE(sk->sk_prot)
->I
)
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
d5bee7374b