From: Jakub Kicinski Date: Thu, 25 May 2023 05:17:41 +0000 (-0700) Subject: tls: improve lockless access safety of tls_err_abort() X-Git-Tag: v6.6.7~2747^2~26 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8a0d57df8938e9fd2e99d47a85b7f37d86f91097;p=platform%2Fkernel%2Flinux-starfive.git tls: improve lockless access safety of tls_err_abort() Most protos' poll() methods insert a memory barrier between writes to sk_err and sk_error_report(). This dates back to commit a4d258036ed9 ("tcp: Fix race in tcp_poll"). I guess we should do the same thing in TLS, tcp_poll() does not hold the socket lock. Fixes: 3c4d7559159b ("tls: kernel TLS support") Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c index da95abb..f37f4a0 100644 --- a/net/tls/tls_strp.c +++ b/net/tls/tls_strp.c @@ -20,7 +20,9 @@ static void tls_strp_abort_strp(struct tls_strparser *strp, int err) strp->stopped = 1; /* Report an error on the lower socket */ - strp->sk->sk_err = -err; + WRITE_ONCE(strp->sk->sk_err, -err); + /* Paired with smp_rmb() in tcp_poll() */ + smp_wmb(); sk_error_report(strp->sk); } diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 6e6a7c3..1a53c8f 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -70,7 +70,9 @@ noinline void tls_err_abort(struct sock *sk, int err) { WARN_ON_ONCE(err >= 0); /* sk->sk_err should contain a positive error code. */ - sk->sk_err = -err; + WRITE_ONCE(sk->sk_err, -err); + /* Paired with smp_rmb() in tcp_poll() */ + smp_wmb(); sk_error_report(sk); }