B.A.T.M.A.N April 2022

b.a.t.m.a.n@lists.open-mesh.org

7 participants
17 discussions

[PATCH] batman-adv: Don't skb_split skbuffs with frag_list
by Sven Eckelmann 16 Apr '22

16 Apr '22

The receiving interface might have used GRO to receive more fragments than MAX_SKB_FRAGS fragments. In this case, these will not be stored in skb_shinfo(skb)->frags but merged into the frag list. batman-adv relies on the function skb_split to split packets up into multiple smaller packets which are not larger than the MTU on the outgoing interface. But this function cannot handle frag_list entries and is only operating on skb_shinfo(skb)->frags. If it is then still trying to split such an skb and xmit'ing it on an interface without support for NETIF_F_FRAGLIST then validate_xmit_skb() will try to linearize it. But this fails due to inconsistent information and __pskb_pull_tail will trigger a BUG_ON after skb_copy_bits() returns an error. In case of entries in frag_list, just linearize the skb before operating on it with skb_split(). Reported-by: Felix Kaechele <felix(a)kaechele.ca> Fixes: 9de347143505 ("batman-adv: layer2 unicast packet fragmentation") Signed-off-by: Sven Eckelmann <sven(a)narfation.org> --- net/batman-adv/fragmentation.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 0899a729..c120c7c6 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -475,6 +475,17 @@ int batadv_frag_send_packet(struct sk_buff *skb, goto free_skb; } + /* GRO might have added fragments to the fragment list instead of + * frags[]. But this is not handled by skb_split and must be + * linearized to avoid incorrect length information after all + * batman-adv fragments were created and submitted to the + * hard-interface + */ + if (skb_has_frag_list(skb) && __skb_linearize(skb)) { + ret = -ENOMEM; + goto free_skb; + } + /* Create one header to be copied to all fragments */ frag_header.packet_type = BATADV_UNICAST_FRAG; frag_header.version = BATADV_COMPAT_VERSION; -- 2.30.2

3 4

Kernel crash when using batman-adv 2022.0 over VXLAN
by Felix Kaechele 16 Apr '22

16 Apr '22

Hi there, I am seeing odd kernel crashes when using batman-adv over VXLAN. This is in a Freifunk environment on our VPN gateway side where clients connect using L2TPv3 tunnels and the gateways are interconnected using VXLAN. The setup is as follows on both ends: - Both machines are Hetzner Cloud VMs (CX11) - OS: Fedora 36 (Pre-release) / Kernel 5.17.2-300.fc36.x86_64 - batctl 2022.0 [batman-adv: 2022.0] (using mainline module provided by - the distro's kernel-modules-extras package) - VXLAN on UDP going out through the WAN connection to the other machines - VXLAN FDB using unicast with static flooding (00:00:00:00:00:00 MAC entries with dst configured) - VXLAN connectivity is confirmed to be working between all connected gateways using IP and ICMP - batctl if add <vxlan-interface> - There is also another bridge attached to the batman-adv interface that bundles all the L2TPv3 tunnels. It has bridge port isolation enabled to prevent the nodes from believing that they are connected to each other on the same L2 network. The mesh is a fairly busy mesh with ~150 nodes and 250-350 client devices at any given time. We currently use 4 gateways (instances with batman-adv in gateway mode). So far I have been able to figure out the follwing: - The issue usually happens within 1-2 minutes of a certain(?) client connecting to the machine using a L2TPv3 tunnel - The issue does not manifest itself when using GRETAP interfaces between the gateway machines in matching pairs on either side of the link and those GRETAP interfaces being added to the batman-adv interface - The number of gateways interconnected using VXLAN does not matter. N-1 machines will crash with this issue and the crashes are rolling in nature, disabling all gateways but one within the N*1-2 minute timeframe. - I remember fighting this issue way back in the past (I think it was around 2017), so this issue has been there for a while in our setup. I have attached a kdump dmesg log that has the panic message. A vmcore file is available for kernel-5.17.2-300.fc36.x86_64, which I can provide if needed. It is 77MB. Thanks, Felix

2 1

[PATCH AUTOSEL 5.4 10/37] ipv6: make mc_forwarding atomic
by Sasha Levin 01 Apr '22

01 Apr '22

From: Eric Dumazet <edumazet(a)google.com> [ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ] This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6() Signed-off-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- include/linux/ipv6.h | 2 +- net/batman-adv/multicast.c | 2 +- net/ipv6/addrconf.c | 4 ++-- net/ipv6/ip6_input.c | 2 +- net/ipv6/ip6mr.c | 8 ++++---- 5 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index bbe297bbbca5..d5c507311efb 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -50,7 +50,7 @@ struct ipv6_devconf { __s32 use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - __s32 mc_forwarding; + atomic_t mc_forwarding; #endif __s32 disable_ipv6; __s32 drop_unicast_in_l2_multicast; diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 09d81f9c2a64..6f0a9f439233 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -136,7 +136,7 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) { struct inet6_dev *in6_dev = __in6_dev_get(dev); - if (in6_dev && in6_dev->cnf.mc_forwarding) + if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding)) return BATADV_NO_FLAGS; else return BATADV_MCAST_WANT_NO_RTR6; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 60d070b25484..69aef71f32ea 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -542,7 +542,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex, #ifdef CONFIG_IPV6_MROUTE if ((all || type == NETCONFA_MC_FORWARDING) && nla_put_s32(skb, NETCONFA_MC_FORWARDING, - devconf->mc_forwarding) < 0) + atomic_read(&devconf->mc_forwarding)) < 0) goto nla_put_failure; #endif if ((all || type == NETCONFA_PROXY_NEIGH) && @@ -5460,7 +5460,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding; + array[DEVCONF_MC_FORWARDING] = atomic_read(&cnf->mc_forwarding); #endif array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6; array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad; diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 7e5df23cbe7b..e6c4966aa956 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -485,7 +485,7 @@ int ip6_mc_input(struct sk_buff *skb) /* * IPv6 multicast router mode is now supported ;) */ - if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && + if (atomic_read(&dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding) && !(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index aee1f6bc039a..6248e00c2bf7 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -736,7 +736,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding--; + atomic_dec(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -904,7 +904,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding++; + atomic_inc(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -1553,7 +1553,7 @@ static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk) } else { rcu_assign_pointer(mrt->mroute_sk, sk); sock_set_flag(sk, SOCK_RCU_FREE); - net->ipv6.devconf_all->mc_forwarding++; + atomic_inc(&net->ipv6.devconf_all->mc_forwarding); } write_unlock_bh(&mrt_lock); @@ -1586,7 +1586,7 @@ int ip6mr_sk_done(struct sock *sk) * so the RCU grace period before sk freeing * is guaranteed by sk_destruct() */ - net->ipv6.devconf_all->mc_forwarding--; + atomic_dec(&net->ipv6.devconf_all->mc_forwarding); write_unlock_bh(&mrt_lock); inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, -- 2.34.1

1 0

[PATCH AUTOSEL 5.10 18/65] ipv6: make mc_forwarding atomic
by Sasha Levin 01 Apr '22

01 Apr '22

From: Eric Dumazet <edumazet(a)google.com> [ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ] This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6() Signed-off-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- include/linux/ipv6.h | 2 +- net/batman-adv/multicast.c | 2 +- net/ipv6/addrconf.c | 4 ++-- net/ipv6/ip6_input.c | 2 +- net/ipv6/ip6mr.c | 8 ++++---- 5 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index f514a7dd8c9c..510f87656479 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -50,7 +50,7 @@ struct ipv6_devconf { __s32 use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - __s32 mc_forwarding; + atomic_t mc_forwarding; #endif __s32 disable_ipv6; __s32 drop_unicast_in_l2_multicast; diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 139894ca788b..c8a341cd652c 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -136,7 +136,7 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) { struct inet6_dev *in6_dev = __in6_dev_get(dev); - if (in6_dev && in6_dev->cnf.mc_forwarding) + if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding)) return BATADV_NO_FLAGS; else return BATADV_MCAST_WANT_NO_RTR6; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 7c5bf39dca5d..86bcb1825698 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -542,7 +542,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex, #ifdef CONFIG_IPV6_MROUTE if ((all || type == NETCONFA_MC_FORWARDING) && nla_put_s32(skb, NETCONFA_MC_FORWARDING, - devconf->mc_forwarding) < 0) + atomic_read(&devconf->mc_forwarding)) < 0) goto nla_put_failure; #endif if ((all || type == NETCONFA_PROXY_NEIGH) && @@ -5515,7 +5515,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding; + array[DEVCONF_MC_FORWARDING] = atomic_read(&cnf->mc_forwarding); #endif array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6; array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad; diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 06d60662717d..15ea3d082534 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -509,7 +509,7 @@ int ip6_mc_input(struct sk_buff *skb) /* * IPv6 multicast router mode is now supported ;) */ - if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && + if (atomic_read(&dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding) && !(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 41cb348a7c3c..5f0ac47acc74 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -740,7 +740,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding--; + atomic_dec(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -908,7 +908,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding++; + atomic_inc(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -1558,7 +1558,7 @@ static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk) } else { rcu_assign_pointer(mrt->mroute_sk, sk); sock_set_flag(sk, SOCK_RCU_FREE); - net->ipv6.devconf_all->mc_forwarding++; + atomic_inc(&net->ipv6.devconf_all->mc_forwarding); } write_unlock_bh(&mrt_lock); @@ -1591,7 +1591,7 @@ int ip6mr_sk_done(struct sock *sk) * so the RCU grace period before sk freeing * is guaranteed by sk_destruct() */ - net->ipv6.devconf_all->mc_forwarding--; + atomic_dec(&net->ipv6.devconf_all->mc_forwarding); write_unlock_bh(&mrt_lock); inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, -- 2.34.1

1 0

[PATCH AUTOSEL 5.15 27/98] ipv6: make mc_forwarding atomic
by Sasha Levin 01 Apr '22

01 Apr '22

From: Eric Dumazet <edumazet(a)google.com> [ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ] This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6() Signed-off-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- include/linux/ipv6.h | 2 +- net/batman-adv/multicast.c | 2 +- net/ipv6/addrconf.c | 4 ++-- net/ipv6/ip6_input.c | 2 +- net/ipv6/ip6mr.c | 8 ++++---- 5 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 07cba0b3496d..d1f386430795 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -51,7 +51,7 @@ struct ipv6_devconf { __s32 use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - __s32 mc_forwarding; + atomic_t mc_forwarding; #endif __s32 disable_ipv6; __s32 drop_unicast_in_l2_multicast; diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 6e3419beca09..2853634a3979 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -134,7 +134,7 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) { struct inet6_dev *in6_dev = __in6_dev_get(dev); - if (in6_dev && in6_dev->cnf.mc_forwarding) + if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding)) return BATADV_NO_FLAGS; else return BATADV_MCAST_WANT_NO_RTR6; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 1fe27807e471..3a8838b79bb6 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -552,7 +552,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex, #ifdef CONFIG_IPV6_MROUTE if ((all || type == NETCONFA_MC_FORWARDING) && nla_put_s32(skb, NETCONFA_MC_FORWARDING, - devconf->mc_forwarding) < 0) + atomic_read(&devconf->mc_forwarding)) < 0) goto nla_put_failure; #endif if ((all || type == NETCONFA_PROXY_NEIGH) && @@ -5537,7 +5537,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding; + array[DEVCONF_MC_FORWARDING] = atomic_read(&cnf->mc_forwarding); #endif array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6; array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad; diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 80256717868e..d4b1e2c5aa76 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -508,7 +508,7 @@ int ip6_mc_input(struct sk_buff *skb) /* * IPv6 multicast router mode is now supported ;) */ - if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && + if (atomic_read(&dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding) && !(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 6a4065d81aa9..91f1c5f56d5f 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -739,7 +739,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding--; + atomic_dec(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -907,7 +907,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding++; + atomic_inc(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -1557,7 +1557,7 @@ static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk) } else { rcu_assign_pointer(mrt->mroute_sk, sk); sock_set_flag(sk, SOCK_RCU_FREE); - net->ipv6.devconf_all->mc_forwarding++; + atomic_inc(&net->ipv6.devconf_all->mc_forwarding); } write_unlock_bh(&mrt_lock); @@ -1590,7 +1590,7 @@ int ip6mr_sk_done(struct sock *sk) * so the RCU grace period before sk freeing * is guaranteed by sk_destruct() */ - net->ipv6.devconf_all->mc_forwarding--; + atomic_dec(&net->ipv6.devconf_all->mc_forwarding); write_unlock_bh(&mrt_lock); inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, -- 2.34.1

1 0

[PATCH AUTOSEL 5.16 033/109] ipv6: make mc_forwarding atomic
by Sasha Levin 01 Apr '22

01 Apr '22

From: Eric Dumazet <edumazet(a)google.com> [ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ] This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6() Signed-off-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- include/linux/ipv6.h | 2 +- net/batman-adv/multicast.c | 2 +- net/ipv6/addrconf.c | 4 ++-- net/ipv6/ip6_input.c | 2 +- net/ipv6/ip6mr.c | 8 ++++---- 5 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index a59d25f19385..b8641dc0ee66 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -51,7 +51,7 @@ struct ipv6_devconf { __s32 use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - __s32 mc_forwarding; + atomic_t mc_forwarding; #endif __s32 disable_ipv6; __s32 drop_unicast_in_l2_multicast; diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index f4004cf0ff6f..9f311fddfaf9 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -134,7 +134,7 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) { struct inet6_dev *in6_dev = __in6_dev_get(dev); - if (in6_dev && in6_dev->cnf.mc_forwarding) + if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding)) return BATADV_NO_FLAGS; else return BATADV_MCAST_WANT_NO_RTR6; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index e92ca415756a..4f64fb285af7 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -554,7 +554,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex, #ifdef CONFIG_IPV6_MROUTE if ((all || type == NETCONFA_MC_FORWARDING) && nla_put_s32(skb, NETCONFA_MC_FORWARDING, - devconf->mc_forwarding) < 0) + atomic_read(&devconf->mc_forwarding)) < 0) goto nla_put_failure; #endif if ((all || type == NETCONFA_PROXY_NEIGH) && @@ -5539,7 +5539,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding; + array[DEVCONF_MC_FORWARDING] = atomic_read(&cnf->mc_forwarding); #endif array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6; array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad; diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 80256717868e..d4b1e2c5aa76 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -508,7 +508,7 @@ int ip6_mc_input(struct sk_buff *skb) /* * IPv6 multicast router mode is now supported ;) */ - if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && + if (atomic_read(&dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding) && !(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 6a4065d81aa9..91f1c5f56d5f 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -739,7 +739,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding--; + atomic_dec(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -907,7 +907,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding++; + atomic_inc(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -1557,7 +1557,7 @@ static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk) } else { rcu_assign_pointer(mrt->mroute_sk, sk); sock_set_flag(sk, SOCK_RCU_FREE); - net->ipv6.devconf_all->mc_forwarding++; + atomic_inc(&net->ipv6.devconf_all->mc_forwarding); } write_unlock_bh(&mrt_lock); @@ -1590,7 +1590,7 @@ int ip6mr_sk_done(struct sock *sk) * so the RCU grace period before sk freeing * is guaranteed by sk_destruct() */ - net->ipv6.devconf_all->mc_forwarding--; + atomic_dec(&net->ipv6.devconf_all->mc_forwarding); write_unlock_bh(&mrt_lock); inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, -- 2.34.1

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[PATCH AUTOSEL 5.17 044/149] ipv6: make mc_forwarding atomic
by Sasha Levin 01 Apr '22

01 Apr '22

From: Eric Dumazet <edumazet(a)google.com> [ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ] This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6() Signed-off-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- include/linux/ipv6.h | 2 +- net/batman-adv/multicast.c | 2 +- net/ipv6/addrconf.c | 4 ++-- net/ipv6/ip6_input.c | 2 +- net/ipv6/ip6mr.c | 8 ++++---- 5 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index a59d25f19385..b8641dc0ee66 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -51,7 +51,7 @@ struct ipv6_devconf { __s32 use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - __s32 mc_forwarding; + atomic_t mc_forwarding; #endif __s32 disable_ipv6; __s32 drop_unicast_in_l2_multicast; diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index f4004cf0ff6f..9f311fddfaf9 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -134,7 +134,7 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) { struct inet6_dev *in6_dev = __in6_dev_get(dev); - if (in6_dev && in6_dev->cnf.mc_forwarding) + if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding)) return BATADV_NO_FLAGS; else return BATADV_MCAST_WANT_NO_RTR6; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f908e2fd30b2..4df84013c4e6 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -554,7 +554,7 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex, #ifdef CONFIG_IPV6_MROUTE if ((all || type == NETCONFA_MC_FORWARDING) && nla_put_s32(skb, NETCONFA_MC_FORWARDING, - devconf->mc_forwarding) < 0) + atomic_read(&devconf->mc_forwarding)) < 0) goto nla_put_failure; #endif if ((all || type == NETCONFA_PROXY_NEIGH) && @@ -5539,7 +5539,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_USE_OPTIMISTIC] = cnf->use_optimistic; #endif #ifdef CONFIG_IPV6_MROUTE - array[DEVCONF_MC_FORWARDING] = cnf->mc_forwarding; + array[DEVCONF_MC_FORWARDING] = atomic_read(&cnf->mc_forwarding); #endif array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6; array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad; diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index 80256717868e..d4b1e2c5aa76 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -508,7 +508,7 @@ int ip6_mc_input(struct sk_buff *skb) /* * IPv6 multicast router mode is now supported ;) */ - if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding && + if (atomic_read(&dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding) && !(ipv6_addr_type(&hdr->daddr) & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)) && likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) { diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 8a2db926b5eb..e3c884678dbe 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -734,7 +734,7 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding--; + atomic_dec(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -902,7 +902,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, in6_dev = __in6_dev_get(dev); if (in6_dev) { - in6_dev->cnf.mc_forwarding++; + atomic_inc(&in6_dev->cnf.mc_forwarding); inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, dev->ifindex, &in6_dev->cnf); @@ -1553,7 +1553,7 @@ static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk) } else { rcu_assign_pointer(mrt->mroute_sk, sk); sock_set_flag(sk, SOCK_RCU_FREE); - net->ipv6.devconf_all->mc_forwarding++; + atomic_inc(&net->ipv6.devconf_all->mc_forwarding); } write_unlock_bh(&mrt_lock); @@ -1586,7 +1586,7 @@ int ip6mr_sk_done(struct sock *sk) * so the RCU grace period before sk freeing * is guaranteed by sk_destruct() */ - net->ipv6.devconf_all->mc_forwarding--; + atomic_dec(&net->ipv6.devconf_all->mc_forwarding); write_unlock_bh(&mrt_lock); inet6_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING, -- 2.34.1

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