Commit 7bf9e18d authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

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: 432e05d3 ("net: ipv4: Control SKB reprioritization after forwarding")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 60c158dc

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

+2 −1
Original line number Diff line number Diff line
@@ -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);

net/ipv4/ip_forward.c

+1 −1
Original line number Diff line number Diff line
@@ -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,