linux/net/bridge, branch v5.10

bridge: Fix a deadlock when enabling multicast snooping

2020-12-08T01:14:43Z

When enabling multicast snooping, bridge module deadlocks on multicast_lock if 1) IPv6 is enabled, and 2) there is an existing querier on the same L2 network. The deadlock was caused by the following sequence: While holding the lock, br_multicast_open calls br_multicast_join_snoopers, which eventually causes IP stack to (attempt to) send out a Listener Report (in igmp6_join_group). Since the destination Ethernet address is a multicast address, br_dev_xmit feeds the packet back to the bridge via br_multicast_rcv, which in turn calls br_multicast_add_group, which then deadlocks on multicast_lock. The fix is to move the call br_multicast_join_snoopers outside of the critical section. This works since br_multicast_join_snoopers only deals with IP and does not modify any multicast data structures of the bridge, so there's no need to hold the lock. Steps to reproduce: 1. sysctl net.ipv6.conf.all.force_mld_version=1 2. have another querier 3. ip link set dev bridge type bridge mcast_snooping 0 && \ ip link set dev bridge type bridge mcast_snooping 1 < deadlock > A typical call trace looks like the following: [ 936.251495] _raw_spin_lock+0x5c/0x68 [ 936.255221] br_multicast_add_group+0x40/0x170 [bridge] [ 936.260491] br_multicast_rcv+0x7ac/0xe30 [bridge] [ 936.265322] br_dev_xmit+0x140/0x368 [bridge] [ 936.269689] dev_hard_start_xmit+0x94/0x158 [ 936.273876] __dev_queue_xmit+0x5ac/0x7f8 [ 936.277890] dev_queue_xmit+0x10/0x18 [ 936.281563] neigh_resolve_output+0xec/0x198 [ 936.285845] ip6_finish_output2+0x240/0x710 [ 936.290039] __ip6_finish_output+0x130/0x170 [ 936.294318] ip6_output+0x6c/0x1c8 [ 936.297731] NF_HOOK.constprop.0+0xd8/0xe8 [ 936.301834] igmp6_send+0x358/0x558 [ 936.305326] igmp6_join_group.part.0+0x30/0xf0 [ 936.309774] igmp6_group_added+0xfc/0x110 [ 936.313787] __ipv6_dev_mc_inc+0x1a4/0x290 [ 936.317885] ipv6_dev_mc_inc+0x10/0x18 [ 936.321677] br_multicast_open+0xbc/0x110 [bridge] [ 936.326506] br_multicast_toggle+0xec/0x140 [bridge] Fixes: 4effd28c1245 ("bridge: join all-snoopers multicast address") Signed-off-by: Joseph Huang Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/20201204235628.50653-1-Joseph.Huang@garmin.com Signed-off-by: Jakub Kicinski

net: bridge: vlan: fix error return code in __vlan_add()

2020-12-04T23:41:06Z

Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: f8ed289fab84 ("bridge: vlan: use br_vlan_(get|put)_master to deal with refcounts") Reported-by: Hulk Robot Signed-off-by: Zhang Changzhong Acked-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/1607071737-33875-1-git-send-email-zhangchangzhong@huawei.com Signed-off-by: Jakub Kicinski

netfilter: bridge: reset skb->pkt_type after NF_INET_POST_ROUTING traversal

2020-11-28T19:46:51Z

Netfilter changes PACKET_OTHERHOST to PACKET_HOST before invoking the hooks as, while it's an expected value for a bridge, routing expects PACKET_HOST. The change is undone later on after hook traversal. This can be seen with pairs of functions updating skb>pkt_type and then reverting it to its original value: For hook NF_INET_PRE_ROUTING: setup_pre_routing / br_nf_pre_routing_finish For hook NF_INET_FORWARD: br_nf_forward_ip / br_nf_forward_finish But the third case where netfilter does this, for hook NF_INET_POST_ROUTING, the packet type is changed in br_nf_post_routing but never reverted. A comment says: /* We assume any code from br_dev_queue_push_xmit onwards doesn't care * about the value of skb->pkt_type. */ But when having a tunnel (say vxlan) attached to a bridge we have the following call trace: br_nf_pre_routing br_nf_pre_routing_ipv6 br_nf_pre_routing_finish br_nf_forward_ip br_nf_forward_finish br_nf_post_routing <- pkt_type is updated to PACKET_HOST br_nf_dev_queue_xmit <- but not reverted to its original value vxlan_xmit vxlan_xmit_one skb_tunnel_check_pmtu <- a check on pkt_type is performed In this specific case, this creates issues such as when an ICMPv6 PTB should be sent back. When CONFIG_BRIDGE_NETFILTER is enabled, the PTB isn't sent (as skb_tunnel_check_pmtu checks if pkt_type is PACKET_HOST and returns early). If the comment is right and no one cares about the value of skb->pkt_type after br_dev_queue_push_xmit (which isn't true), resetting it to its original value should be safe. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Antoine Tenart Reviewed-by: Florian Westphal Link: https://lore.kernel.org/r/20201123174902.622102-1-atenart@kernel.org Signed-off-by: Jakub Kicinski

net: bridge: add missing counters to ndo_get_stats64 callback

2020-11-16T23:47:50Z

In br_forward.c and br_input.c fields dev->stats.tx_dropped and dev->stats.multicast are populated, but they are ignored in ndo_get_stats64. Fixes: 28172739f0a2 ("net: fix 64 bit counters on 32 bit arches") Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/58ea9963-77ad-a7cf-8dfd-fc95ab95f606@gmail.com Signed-off-by: Jakub Kicinski

netfilter: ebtables: Fixes dropping of small packets in bridge nat

2020-10-20T11:54:53Z

Fixes an error causing small packets to get dropped. skb_ensure_writable expects the second parameter to be a length in the ethernet payload.=20 If we want to write the ethernet header (src, dst), we should pass 0. Otherwise, packets with small payloads (< ETH_ALEN) will get dropped. Fixes: c1a831167901 ("netfilter: bridge: convert skb_make_writable to skb_ensure_writable") Signed-off-by: Timothée COCAULT Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

net: bridge: use new function dev_fetch_sw_netstats

2020-10-14T00:33:49Z

Simplify the code by using new function dev_fetch_sw_netstats(). Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/d1c3ff29-5691-9d54-d164-16421905fa59@gmail.com Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-10-08T22:44:50Z

Small conflict around locking in rxrpc_process_event() - channel_lock moved to bundle in next, while state lock needs _bh() from net. Signed-off-by: Jakub Kicinski

bridge: Netlink interface fix.

2020-10-08T19:05:07Z

This commit is correcting NETLINK br_fill_ifinfo() to be able to handle 'filter_mask' with multiple flags asserted. Fixes: 36a8e8e265420 ("bridge: Extend br_fill_ifinfo to return MPR status") Signed-off-by: Henrik Bjoernlund Reviewed-by: Horatiu Vultur Suggested-by: Nikolay Aleksandrov Tested-by: Horatiu Vultur Acked-by: Nikolay Aleksandrov Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-10-06T01:40:01Z

Rejecting non-native endian BTF overlapped with the addition of support for it. The rest were more simple overlapping changes, except the renesas ravb binding update, which had to follow a file move as well as a YAML conversion. Signed-off-by: David S. Miller

net: core: introduce struct netdev_nested_priv for nested interface infrastructure

2020-09-28T22:00:15Z

Functions related to nested interface infrastructure such as netdev_walk_all_{ upper | lower }_dev() pass both private functions and "data" pointer to handle their own things. At this point, the data pointer type is void *. In order to make it easier to expand common variables and functions, this new netdev_nested_priv structure is added. In the following patch, a new member variable will be added into this struct to fix the lockdep issue. Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller