From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0730B2EFDA1 for ; Sat, 28 Feb 2026 22:18:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772317088; cv=none; b=oJDmW5Kkr4zVxs+Hay1y4eF80MqT0nmjXq0MRI7Srno/5LNwXUVvsb/tPEfzrWaX3hmX4JERQ2PRCoeOTJ+T1Bjoat4hBmDwGBMD+z0cTxazwRM0xtY76p/Tpsa+b8CdAYB24kyM2Ox+t19+mOlr36tK2ejWw/N//oEhAg2thwM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772317088; c=relaxed/simple; bh=o/D8LhkHgxda7DTaDVDacd8sZ7w/MX3WeN/tyWbDFuY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=R6bRb1LwwtL7RyBoe+01/rWJ3p8aNNB9BvSqGdv0vTiMrF+LwId/c/d+f84Nh4AqM9/Ks7LzzbwOkMag1+wH5KsGjiyPbOm2DsbFH+oXS+xeEDBPa9Qa4w1qC9C57jrRFXmM6XtlJXjuJgFsJZ83NRuEqEkWaiVBGQR4ttpAO5M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=xJLWbnum; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--kuniyu.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="xJLWbnum" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2addefa321dso189254215ad.3 for ; Sat, 28 Feb 2026 14:18:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772317086; x=1772921886; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=MrENbbwGTF9kqD99WTwTyYRww8UwmJ1+L436dBwgMhY=; b=xJLWbnumem75UTppNJuu4ucDHIwbjOIHECBEzIYx5FAo+IaJyzPfnuKBnPdibc2q/i PviJVq7DGnmAu/cAo88HS2BqCDNdUVB0nOYhxMZyBRiMZDKbQYlamrjARXiwGAS26arF G8aiGyw3w5WKjkdk4CZu0t1G24ub/Qpa27tKP4PwxyrcedEXCthqpT88z5ORvZ5ijyzJ L2vRH/doLNReqh+CNlUd/cCcHSQTS+DkXUVrz7ty9xCXZ7Hvs/RzpGFEOp5/pcZxxcKK pIwMcJkyhdU3og2KkGB53ISV24xw3XBVcdqGunqrBkQL5eapKFqPCEa4EtBjUfxy6fJT TYww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772317086; x=1772921886; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=MrENbbwGTF9kqD99WTwTyYRww8UwmJ1+L436dBwgMhY=; b=kJolSvD2NEeTX7Ggcno/l0mpyZ4asmVFhzusxlEmSxYfJOu1fCcfhbIn8v9dY7efxT wyGj11NFJHhPQFeErz8zcr/PeeFTT++diFVBdyMM46LH+BkyIu4Ta6YSpnUuDbBmNz4B 0vONnzmu+qQubTUi+YRgXziiaazDRWvYRUti9BWIGScOKGoh/6rU3YNBLbj1LWVefmB0 Bt9Obk6uw3tr1PROX//8MGctTIFK39/V8m3Mh/2Q8cYvUzgt3jtvgSQu6RpnVwcMxpMu QDfcr6i8nzdlecKsZfc2ulKlVfnzJ4AYcYEPOjqsITtrhQJKLXPdrbWsdzDFKtDh7WHq HtNA== X-Forwarded-Encrypted: i=1; AJvYcCVqh+tOFfsjpf4rG0DcwnW6ZhhWGyI6vVyW5FsPM68z784H4Jgkenuqh+mgSuYhs6SHL5fHLJA=@vger.kernel.org X-Gm-Message-State: AOJu0YxOLZ25OeUnA+EGMO3kpShke5nRxO44qQklNeoRHIzQ9YM77cOr 7m8W2ByCI8zy3MGjW63o7vBiCUGwXZaWm2tzvPWoDtXHpcILVbf/Y6uZg0oG8MNzUdwgrnzCuCK Gfo6cyA== X-Received: from plbku4.prod.google.com ([2002:a17:903:2884:b0:2a3:e79c:6cfb]) (user=kuniyu job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:d48d:b0:2aa:d802:a010 with SMTP id d9443c01a7336-2ae2e3e71fdmr67773455ad.10.1772317086201; Sat, 28 Feb 2026 14:18:06 -0800 (PST) Date: Sat, 28 Feb 2026 22:17:20 +0000 In-Reply-To: <20260228221800.1082070-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260228221800.1082070-1-kuniyu@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260228221800.1082070-3-kuniyu@google.com> Subject: [PATCH v3 net-next 02/15] ipmr: Annotate access to mrt->mroute_do_{pim,assert,wrvifwhole}. From: Kuniyuki Iwashima To: "David S . Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" These fields in struct mr_table are updated in ip_mroute_setsockopt() under RTNL: * mroute_do_pim * mroute_do_assert * mroute_do_wrvifwhole However, ip_mroute_getsockopt() does not hold RTNL and read the first two fields locklessly, and ip_mr_forward() reads all the three under RCU. pim_rcv_v1() also reads mroute_do_pim locklessly. Let's use WRITE_ONCE() and READ_ONCE() for them. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet --- v3: Use READ_ONCE() for mrt->mroute_do_pim in ip_mr_forward() and pim_rcv_v1() --- net/ipv4/ipmr.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 131382c388e9..970f173654c7 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -1506,7 +1506,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval, ret = -EFAULT; break; } - mrt->mroute_do_assert = val; + WRITE_ONCE(mrt->mroute_do_assert, val); break; case MRT_PIM: if (!ipmr_pimsm_enabled()) { @@ -1525,9 +1525,9 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval, do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE); val = !!val; if (val != mrt->mroute_do_pim) { - mrt->mroute_do_pim = val; - mrt->mroute_do_assert = val; - mrt->mroute_do_wrvifwhole = do_wrvifwhole; + WRITE_ONCE(mrt->mroute_do_pim, val); + WRITE_ONCE(mrt->mroute_do_assert, val); + WRITE_ONCE(mrt->mroute_do_wrvifwhole, do_wrvifwhole); } break; case MRT_TABLE: @@ -1610,10 +1610,10 @@ int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval, case MRT_PIM: if (!ipmr_pimsm_enabled()) return -ENOPROTOOPT; - val = mrt->mroute_do_pim; + val = READ_ONCE(mrt->mroute_do_pim); break; case MRT_ASSERT: - val = mrt->mroute_do_assert; + val = READ_ONCE(mrt->mroute_do_assert); break; default: return -ENOPROTOOPT; @@ -2037,20 +2037,20 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt, atomic_long_inc(&c->_c.mfc_un.res.wrong_if); - if (true_vifi >= 0 && mrt->mroute_do_assert && + if (true_vifi >= 0 && READ_ONCE(mrt->mroute_do_assert) && /* pimsm uses asserts, when switching from RPT to SPT, * so that we cannot check that packet arrived on an oif. * It is bad, but otherwise we would need to move pretty * large chunk of pimd to kernel. Ough... --ANK */ - (mrt->mroute_do_pim || + (READ_ONCE(mrt->mroute_do_pim) || c->_c.mfc_un.res.ttls[true_vifi] < 255) && time_after(jiffies, c->_c.mfc_un.res.last_assert + MFC_ASSERT_THRESH)) { c->_c.mfc_un.res.last_assert = jiffies; ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF); - if (mrt->mroute_do_wrvifwhole) + if (READ_ONCE(mrt->mroute_do_wrvifwhole)) ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRVIFWHOLE); } @@ -2358,7 +2358,7 @@ int pim_rcv_v1(struct sk_buff *skb) mrt = ipmr_rt_fib_lookup(net, skb); if (IS_ERR(mrt)) goto drop; - if (!mrt->mroute_do_pim || + if (!READ_ONCE(mrt->mroute_do_pim) || pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) goto drop; -- 2.53.0.473.g4a7958ca14-goog