This is a note to let you know that I've just added the patch titled
ip: Fix data-races around sysctl_ip_fwd_update_priority.
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ip-fix-data-races-around-sysctl_ip_fwd_update_priori.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 86610c0280fac8bfb7d6832a67e02dd0529febce
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Wed Jul 13 13:51:54 2022 -0700
ip: Fix data-races around sysctl_ip_fwd_update_priority.
[ Upstream commit 7bf9e18d9a5e99e3c83482973557e9f047b051e7 ]
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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 5ec9bc321566..994bd2e14e55 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -10462,13 +10462,14 @@ 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 92ba3350274b..03bb7c51b618 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -151,7 +151,7 @@ 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,
