diff options
| author | Ido Schimmel <idosch@nvidia.com> | 2025-04-15 15:11:29 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-09 18:58:12 +0200 |
| commit | 02bebe7d0483dc25a4ec230ab67d01433def7f00 (patch) | |
| tree | cd6905c66a5ad2a7b3bcbe94e0df856105c57e4c | |
| parent | 9238419f6de35c2641e093ca8a3d25b5f5375dbb (diff) | |
vxlan: Add RCU read-side critical sections in the Tx path
[ Upstream commit 804b09be09f8af4eda5346a72361459ba21fcf1b ]
The Tx path does not run from an RCU read-side critical section which
makes the current lockless accesses to FDB entries invalid. As far as I
am aware, this has not been a problem in practice, but traces will be
generated once we transition the FDB lookup to rhashtable_lookup().
Add rcu_read_{lock,unlock}() around the handling of FDB entries in the
Tx path. Remove the RCU read-side critical section from vxlan_xmit_nh()
as now the function is always called from an RCU read-side critical
section.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-2-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: 1f5d2fd1ca04 ("vxlan: Fix NPD in {arp,neigh}_reduce() when using nexthop objects")
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/vxlan/vxlan_core.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index 8853fcb7eb7f..1d431e3fc71e 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -1909,12 +1909,15 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni) goto out; } + rcu_read_lock(); f = vxlan_find_mac(vxlan, n->ha, vni); if (f && vxlan_addr_any(&(first_remote_rcu(f)->remote_ip))) { /* bridge-local neighbor */ neigh_release(n); + rcu_read_unlock(); goto out; } + rcu_read_unlock(); reply = arp_create(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, n->ha, sha); @@ -2632,14 +2635,10 @@ static void vxlan_xmit_nh(struct sk_buff *skb, struct net_device *dev, memset(&nh_rdst, 0, sizeof(struct vxlan_rdst)); hash = skb_get_hash(skb); - rcu_read_lock(); nh = rcu_dereference(f->nh); - if (!nh) { - rcu_read_unlock(); + if (!nh) goto drop; - } do_xmit = vxlan_fdb_nh_path_select(nh, hash, &nh_rdst); - rcu_read_unlock(); if (likely(do_xmit)) vxlan_xmit_one(skb, dev, vni, &nh_rdst, did_rsc); @@ -2766,6 +2765,7 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev) } eth = eth_hdr(skb); + rcu_read_lock(); f = vxlan_find_mac(vxlan, eth->h_dest, vni); did_rsc = false; @@ -2788,7 +2788,7 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev) vxlan_vnifilter_count(vxlan, vni, NULL, VXLAN_VNI_STATS_TX_DROPS, 0); kfree_skb_reason(skb, SKB_DROP_REASON_NO_TX_TARGET); - return NETDEV_TX_OK; + goto out; } } @@ -2813,6 +2813,8 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev) kfree_skb_reason(skb, SKB_DROP_REASON_NO_TX_TARGET); } +out: + rcu_read_unlock(); return NETDEV_TX_OK; } |