From 0ab07cfc4f03bd6a2d6ec2762ae70d585bbd7bbf Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Fri, 6 May 2022 22:26:35 +0200 Subject: [PATCH] batman-adv: Merge bugfixes from 2022.1 * Request iflink once in batadv-on-batadv check * Request iflink once in batadv_get_real_netdevice * Don't expect inter-netns unique iflink indices * Don't skb_split skbuffs with frag_list Signed-off-by: Sven Eckelmann --- ...st-iflink-once-in-batadv-on-batadv-c.patch | 44 ++++++++++ ...st-iflink-once-in-batadv_get_real_ne.patch | 46 ++++++++++ ...-expect-inter-netns-unique-iflink-in.patch | 86 +++++++++++++++++++ ...n-t-skb_split-skbuffs-with-frag_list.patch | 46 ++++++++++ 4 files changed, 222 insertions(+) create mode 100644 batman-adv/patches/0008-batman-adv-Request-iflink-once-in-batadv-on-batadv-c.patch create mode 100644 batman-adv/patches/0009-batman-adv-Request-iflink-once-in-batadv_get_real_ne.patch create mode 100644 batman-adv/patches/0010-batman-adv-Don-t-expect-inter-netns-unique-iflink-in.patch create mode 100644 batman-adv/patches/0011-batman-adv-Don-t-skb_split-skbuffs-with-frag_list.patch diff --git a/batman-adv/patches/0008-batman-adv-Request-iflink-once-in-batadv-on-batadv-c.patch b/batman-adv/patches/0008-batman-adv-Request-iflink-once-in-batadv-on-batadv-c.patch new file mode 100644 index 0000000..c117cca --- /dev/null +++ b/batman-adv/patches/0008-batman-adv-Request-iflink-once-in-batadv-on-batadv-c.patch @@ -0,0 +1,44 @@ +From: Sven Eckelmann +Date: Wed, 2 Mar 2022 19:49:44 +0100 +Subject: batman-adv: Request iflink once in batadv-on-batadv check + +There is no need to call dev_get_iflink multiple times for the same +net_device in batadv_is_on_batman_iface. And since some of the +.ndo_get_iflink callbacks are dynamic (for example via RCUs like in +vxcan_get_iflink), it could easily happen that the returned values are not +stable. The pre-checks before __dev_get_by_index are then of course bogus. + +Fixes: 3d48811b27f5 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface") +Signed-off-by: Sven Eckelmann +Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/f6c0c45356fe3ab9c5e01b81d060f8a436658037 + +--- a/net/batman-adv/hard-interface.c ++++ b/net/batman-adv/hard-interface.c +@@ -148,22 +148,23 @@ static bool batadv_is_on_batman_iface(co + struct net *net = dev_net(net_dev); + struct net_device *parent_dev; + struct net *parent_net; ++ int iflink; + bool ret; + + /* check if this is a batman-adv mesh interface */ + if (batadv_softif_is_valid(net_dev)) + return true; + ++ iflink = dev_get_iflink(net_dev); ++ + /* no more parents..stop recursion */ +- if (dev_get_iflink(net_dev) == 0 || +- dev_get_iflink(net_dev) == net_dev->ifindex) ++ if (iflink == 0 || iflink == net_dev->ifindex) + return false; + + parent_net = batadv_getlink_net(net_dev, net); + + /* recurse over the parent device */ +- parent_dev = __dev_get_by_index((struct net *)parent_net, +- dev_get_iflink(net_dev)); ++ parent_dev = __dev_get_by_index((struct net *)parent_net, iflink); + /* if we got a NULL parent_dev there is something broken.. */ + if (!parent_dev) { + pr_err("Cannot find parent device\n"); diff --git a/batman-adv/patches/0009-batman-adv-Request-iflink-once-in-batadv_get_real_ne.patch b/batman-adv/patches/0009-batman-adv-Request-iflink-once-in-batadv_get_real_ne.patch new file mode 100644 index 0000000..d0e1270 --- /dev/null +++ b/batman-adv/patches/0009-batman-adv-Request-iflink-once-in-batadv_get_real_ne.patch @@ -0,0 +1,46 @@ +From: Sven Eckelmann +Date: Wed, 2 Mar 2022 19:49:45 +0100 +Subject: batman-adv: Request iflink once in batadv_get_real_netdevice + +There is no need to call dev_get_iflink multiple times for the same +net_device in batadv_get_real_netdevice. And since some of the +ndo_get_iflink callbacks are dynamic (for example via RCUs like in +vxcan_get_iflink), it could easily happen that the returned values are not +stable. The pre-checks before __dev_get_by_index are then of course bogus. + +Fixes: 2b45bb6c3aad ("batman-adv: additional checks for virtual interfaces on top of WiFi") +Signed-off-by: Sven Eckelmann +Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/445f477ec3e805425186f5fbe8ed0fe89cc226b6 + +--- a/net/batman-adv/hard-interface.c ++++ b/net/batman-adv/hard-interface.c +@@ -214,14 +214,16 @@ static struct net_device *batadv_get_rea + struct net_device *real_netdev = NULL; + struct net *real_net; + struct net *net; +- int ifindex; ++ int iflink; + + ASSERT_RTNL(); + + if (!netdev) + return NULL; + +- if (netdev->ifindex == dev_get_iflink(netdev)) { ++ iflink = dev_get_iflink(netdev); ++ ++ if (netdev->ifindex == iflink) { + dev_hold(netdev); + return netdev; + } +@@ -231,9 +233,8 @@ static struct net_device *batadv_get_rea + goto out; + + net = dev_net(hard_iface->soft_iface); +- ifindex = dev_get_iflink(netdev); + real_net = batadv_getlink_net(netdev, net); +- real_netdev = dev_get_by_index(real_net, ifindex); ++ real_netdev = dev_get_by_index(real_net, iflink); + + out: + batadv_hardif_put(hard_iface); diff --git a/batman-adv/patches/0010-batman-adv-Don-t-expect-inter-netns-unique-iflink-in.patch b/batman-adv/patches/0010-batman-adv-Don-t-expect-inter-netns-unique-iflink-in.patch new file mode 100644 index 0000000..1a7859c --- /dev/null +++ b/batman-adv/patches/0010-batman-adv-Don-t-expect-inter-netns-unique-iflink-in.patch @@ -0,0 +1,86 @@ +From: Sven Eckelmann +Date: Wed, 2 Mar 2022 19:49:46 +0100 +Subject: batman-adv: Don't expect inter-netns unique iflink indices + +The ifindex doesn't have to be unique for multiple network namespaces on +the same machine. + + $ ip netns add test1 + $ ip -net test1 link add dummy1 type dummy + $ ip netns add test2 + $ ip -net test2 link add dummy2 type dummy + + $ ip -net test1 link show dev dummy1 + 6: dummy1: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 + link/ether 96:81:55:1e:dd:85 brd ff:ff:ff:ff:ff:ff + $ ip -net test2 link show dev dummy2 + 6: dummy2: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 + link/ether 5a:3c:af:35:07:c3 brd ff:ff:ff:ff:ff:ff + +But the batman-adv code to walk through the various layers of virtual +interfaces uses this assumption because dev_get_iflink handles it +internally and doesn't return the actual netns of the iflink. And +dev_get_iflink only documents the situation where ifindex == iflink for +physical devices. + +But only checking for dev->netdev_ops->ndo_get_iflink is also not an option +because ipoib_get_iflink implements it even when it sometimes returns an +iflink != ifindex and sometimes iflink == ifindex. The caller must +therefore make sure itself to check both netns and iflink + ifindex for +equality. Only when they are equal, a "physical" interface was detected +which should stop the traversal. On the other hand, vxcan_get_iflink can +also return 0 in case there was currently no valid peer. In this case, it +is still necessary to stop. + +Fixes: 3d48811b27f5 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface") +Fixes: 2b45bb6c3aad ("batman-adv: additional checks for virtual interfaces on top of WiFi") +Reported-by: Sabrina Dubroca +Signed-off-by: Sven Eckelmann +Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/0aac7a9fbbbeec25f2f54a9e6d53ea91217ba720 + +--- a/net/batman-adv/hard-interface.c ++++ b/net/batman-adv/hard-interface.c +@@ -156,13 +156,15 @@ static bool batadv_is_on_batman_iface(co + return true; + + iflink = dev_get_iflink(net_dev); +- +- /* no more parents..stop recursion */ +- if (iflink == 0 || iflink == net_dev->ifindex) ++ if (iflink == 0) + return false; + + parent_net = batadv_getlink_net(net_dev, net); + ++ /* iflink to itself, most likely physical device */ ++ if (net == parent_net && iflink == net_dev->ifindex) ++ return false; ++ + /* recurse over the parent device */ + parent_dev = __dev_get_by_index((struct net *)parent_net, iflink); + /* if we got a NULL parent_dev there is something broken.. */ +@@ -222,8 +224,7 @@ static struct net_device *batadv_get_rea + return NULL; + + iflink = dev_get_iflink(netdev); +- +- if (netdev->ifindex == iflink) { ++ if (iflink == 0) { + dev_hold(netdev); + return netdev; + } +@@ -234,6 +235,14 @@ static struct net_device *batadv_get_rea + + net = dev_net(hard_iface->soft_iface); + real_net = batadv_getlink_net(netdev, net); ++ ++ /* iflink to itself, most likely physical device */ ++ if (net == real_net && netdev->ifindex == iflink) { ++ real_netdev = netdev; ++ dev_hold(real_netdev); ++ goto out; ++ } ++ + real_netdev = dev_get_by_index(real_net, iflink); + + out: diff --git a/batman-adv/patches/0011-batman-adv-Don-t-skb_split-skbuffs-with-frag_list.patch b/batman-adv/patches/0011-batman-adv-Don-t-skb_split-skbuffs-with-frag_list.patch new file mode 100644 index 0000000..4f6f30e --- /dev/null +++ b/batman-adv/patches/0011-batman-adv-Don-t-skb_split-skbuffs-with-frag_list.patch @@ -0,0 +1,46 @@ +From: Sven Eckelmann +Date: Sat, 16 Apr 2022 14:24:34 +0200 +Subject: batman-adv: Don't skb_split skbuffs with frag_list + +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 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 +Tested-by: Felix Kaechele +Fixes: 9de347143505 ("batman-adv: layer2 unicast packet fragmentation") +Signed-off-by: Sven Eckelmann +Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/d467720acaf1b22b0cee58144eeaf9ef6c5e285c + +--- a/net/batman-adv/fragmentation.c ++++ b/net/batman-adv/fragmentation.c +@@ -475,6 +475,17 @@ int batadv_frag_send_packet(struct sk_bu + 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