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Tue, 09 Jul 2024 03:19:56 -0700 (PDT) Received: from kashwindayan-virtual-machine.eng.vmware.com ([66.170.99.1]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70b43967345sm1426016b3a.112.2024.07.09.03.19.55 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Jul 2024 03:19:56 -0700 (PDT) From: Ashwin Kamat To: linux-kernel@vger.kernel.org Cc: gregkh@linuxfoundation.org, davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org, netdev@vger.kernel.org, florian.fainelli@broadcom.com, ajay.kaher@broadcom.com, vasavi.sirnapalli@broadcom.com, tapas.kundu@broadcom.com, ashwin.kamat@broadcom.com, Eric Dumazet , Sasha Levin Subject: [PATCH v5.15 1/2] net/ipv6: annotate data-races around cnf.disable_ipv6 Date: Tue, 9 Jul 2024 15:49:43 +0530 Message-Id: <1720520384-9690-2-git-send-email-ashwin.kamat@broadcom.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1720520384-9690-1-git-send-email-ashwin.kamat@broadcom.com> References: <1720520384-9690-1-git-send-email-ashwin.kamat@broadcom.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Eric Dumazet [Upstream commit d289ab65b89c1d4d88417cb6c03e923f21f95fae] disable_ipv6 is read locklessly, add appropriate READ_ONCE() and WRITE_ONCE() annotations. v2: do not preload net before rtnl_trylock() in addrconf_disable_ipv6() (Jiri) Signed-off-by: Eric Dumazet Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller Stable-dep-of: 4db783d68b9b ("ipv6: prevent NULL dereference in ip6_output(= )") Signed-off-by: Sasha Levin [Ashwin: Regenerated the Patch for v5.15] Signed-off-by: Ashwin Dayanand Kamat --- net/ipv6/addrconf.c | 9 +++++---- net/ipv6/ip6_input.c | 2 +- net/ipv6/ip6_output.c | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index a17e1d744b2d..ba22470b7476 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4131,7 +4131,7 @@ static void addrconf_dad_work(struct work_struct *w) if (!ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) && ipv6_addr_equal(&ifp->addr, &addr)) { /* DAD failed for link-local based on MAC */ - idev->cnf.disable_ipv6 =3D 1; + WRITE_ONCE(idev->cnf.disable_ipv6, 1); =20 pr_info("%s: IPv6 being disabled!\n", ifp->idev->dev->name); @@ -6277,7 +6277,8 @@ static void addrconf_disable_change(struct net *net, = __s32 newf) idev =3D __in6_dev_get(dev); if (idev) { int changed =3D (!idev->cnf.disable_ipv6) ^ (!newf); - idev->cnf.disable_ipv6 =3D newf; + + WRITE_ONCE(idev->cnf.disable_ipv6, newf); if (changed) dev_disable_change(idev); } @@ -6294,7 +6295,7 @@ static int addrconf_disable_ipv6(struct ctl_table *ta= ble, int *p, int newf) =20 net =3D (struct net *)table->extra2; old =3D *p; - *p =3D newf; + WRITE_ONCE(*p, newf); =20 if (p =3D=3D &net->ipv6.devconf_dflt->disable_ipv6) { rtnl_unlock(); @@ -6302,7 +6303,7 @@ static int addrconf_disable_ipv6(struct ctl_table *ta= ble, int *p, int newf) } =20 if (p =3D=3D &net->ipv6.devconf_all->disable_ipv6) { - net->ipv6.devconf_dflt->disable_ipv6 =3D newf; + WRITE_ONCE(net->ipv6.devconf_dflt->disable_ipv6, newf); addrconf_disable_change(net, newf); } else if ((!newf) ^ (!old)) dev_disable_change((struct inet6_dev *)table->extra1); diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 32071529bfd9..c1c29432367c 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -164,7 +164,7 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb= , struct net_device *dev, __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len); =20 if ((skb =3D skb_share_check(skb, GFP_ATOMIC)) =3D=3D NULL || - !idev || unlikely(idev->cnf.disable_ipv6)) { + !idev || unlikely(READ_ONCE(idev->cnf.disable_ipv6))) { __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); goto drop; } diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 7205473ba28d..770ee7ffb0d5 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -221,7 +221,7 @@ int ip6_output(struct net *net, struct sock *sk, struct= sk_buff *skb) skb->protocol =3D htons(ETH_P_IPV6); skb->dev =3D dev; =20 - if (unlikely(idev->cnf.disable_ipv6)) { + if (unlikely(READ_ONCE(idev->cnf.disable_ipv6))) { IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); kfree_skb(skb); return 0; --=20 2.45.1