From 8895a9c2ac76fb9d3922fed4fe092c8ec5e5cccc Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 18 Jul 2022 10:26:41 -0700 Subject: [PATCH] ipv4: Fix data-races around sysctl_fib_multipath_hash_fields. While reading sysctl_fib_multipath_hash_fields, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: ce5c9c20d364 ("ipv4: Add a sysctl to control multipath hash fields") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +- net/ipv4/route.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index de63a5f..85aa1c4 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -10342,7 +10342,7 @@ static void mlxsw_sp_mp4_hash_init(struct mlxsw_sp *mlxsw_sp, mlxsw_sp_mp_hash_inner_l3(config); break; case 3: - hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; + hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); /* Outer */ MLXSW_SP_MP_HASH_HEADER_SET(headers, IPV4_EN_NOT_TCP_NOT_UDP); MLXSW_SP_MP_HASH_HEADER_SET(headers, IPV4_EN_TCP_UDP); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 521194d..4702c61 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1929,7 +1929,7 @@ static u32 fib_multipath_custom_hash_outer(const struct net *net, const struct sk_buff *skb, bool *p_has_inner) { - u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; + u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); struct flow_keys keys, hash_keys; if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) @@ -1958,7 +1958,7 @@ static u32 fib_multipath_custom_hash_inner(const struct net *net, const struct sk_buff *skb, bool has_inner) { - u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; + u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); struct flow_keys keys, hash_keys; /* We assume the packet carries an encapsulation, but if none was @@ -2018,7 +2018,7 @@ static u32 fib_multipath_custom_hash_skb(const struct net *net, static u32 fib_multipath_custom_hash_fl4(const struct net *net, const struct flowi4 *fl4) { - u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields; + u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields); struct flow_keys hash_keys; if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) -- 2.7.4