netdev - [PATCH v1 net 04/15] ip: Fix data-races around sysctl_ip_fwd_update

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 13 Jul 2022 13:51:54 -0700
From:   Kuniyuki Iwashima <kuniyu@...zon.com>
To:     "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        David Ahern <dsahern@...nel.org>
CC:     Kuniyuki Iwashima <kuniyu@...zon.com>,
        Kuniyuki Iwashima <kuni1840@...il.com>,
        <netdev@...r.kernel.org>, Petr Machata <petrm@...dia.com>
Subject: [PATCH v1 net 04/15] ip: Fix data-races around sysctl_ip_fwd_update_priority.

While reading sysctl_ip_fwd_update_priority, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: 432e05d32892 ("net: ipv4: Control SKB reprioritization after forwarding")
Signed-off-by: Kuniyuki Iwashima <kuniyu@...zon.com>
---
CC: Petr Machata <petrm@...dia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 3 ++-
 net/ipv4/ip_forward.c                                 | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 0d8a0068e4ca..868d28f3b4e1 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -10523,13 +10523,14 @@ static int mlxsw_sp_dscp_init(struct mlxsw_sp *mlxsw_sp)
 static int __mlxsw_sp_router_init(struct mlxsw_sp *mlxsw_sp)
 {
 	struct net *net = mlxsw_sp_net(mlxsw_sp);
-	bool usp = net->ipv4.sysctl_ip_fwd_update_priority;
 	char rgcr_pl[MLXSW_REG_RGCR_LEN];
 	u64 max_rifs;
+	bool usp;
 
 	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_RIFS))
 		return -EIO;
 	max_rifs = MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_RIFS);
+	usp = READ_ONCE(net->ipv4.sysctl_ip_fwd_update_priority);
 
 	mlxsw_reg_rgcr_pack(rgcr_pl, true, true);
 	mlxsw_reg_rgcr_max_router_interfaces_set(rgcr_pl, max_rifs);
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index e3aa436a1bdf..e18931a6d153 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -157,7 +157,7 @@ int ip_forward(struct sk_buff *skb)
 	    !skb_sec_path(skb))
 		ip_rt_send_redirect(skb);
 
-	if (net->ipv4.sysctl_ip_fwd_update_priority)
+	if (READ_ONCE(net->ipv4.sysctl_ip_fwd_update_priority))
 		skb->priority = rt_tos2priority(iph->tos);
 
 	return NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
-- 
2.30.2