From 31ca0458a61a502adb7ed192bf9716c6d05791a5 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Wed, 4 May 2016 16:18:45 +0200 Subject: net: bridge: fix old ioctl unlocked net device walk get_bridge_ifindices() is used from the old "deviceless" bridge ioctl calls which aren't called with rtnl held. The comment above says that it is called with rtnl but that is not really the case. Here's a sample output from a test ASSERT_RTNL() which I put in get_bridge_ifindices and executed "brctl show": [ 957.422726] RTNL: assertion failed at net/bridge//br_ioctl.c (30) [ 957.422925] CPU: 0 PID: 1862 Comm: brctl Tainted: G W O 4.6.0-rc4+ #157 [ 957.423009] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 [ 957.423009] 0000000000000000 ffff880058adfdf0 ffffffff8138dec5 0000000000000400 [ 957.423009] ffffffff81ce8380 ffff880058adfe58 ffffffffa05ead32 0000000000000001 [ 957.423009] 00007ffec1a444b0 0000000000000400 ffff880053c19130 0000000000008940 [ 957.423009] Call Trace: [ 957.423009] [] dump_stack+0x85/0xc0 [ 957.423009] [] br_ioctl_deviceless_stub+0x212/0x2e0 [bridge] [ 957.423009] [] sock_ioctl+0x22b/0x290 [ 957.423009] [] do_vfs_ioctl+0x95/0x700 [ 957.423009] [] SyS_ioctl+0x79/0x90 [ 957.423009] [] entry_SYSCALL_64_fastpath+0x23/0xc1 Since it only reads bridge ifindices, we can use rcu to safely walk the net device list. Also remove the wrong rtnl comment above. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- net/bridge/br_ioctl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/bridge') diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c index 263b4de4de57..60a3dbfca8a1 100644 --- a/net/bridge/br_ioctl.c +++ b/net/bridge/br_ioctl.c @@ -21,18 +21,19 @@ #include #include "br_private.h" -/* called with RTNL */ static int get_bridge_ifindices(struct net *net, int *indices, int num) { struct net_device *dev; int i = 0; - for_each_netdev(net, dev) { + rcu_read_lock(); + for_each_netdev_rcu(net, dev) { if (i >= num) break; if (dev->priv_flags & IFF_EBRIDGE) indices[i++] = dev->ifindex; } + rcu_read_unlock(); return i; } -- cgit v1.2.3 From 856ce5d083e14571d051301fe3c65b32b8cbe321 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Linus=20L=C3=BCssing?= Date: Wed, 4 May 2016 17:25:02 +0200 Subject: bridge: fix igmp / mld query parsing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With the newly introduced helper functions the skb pulling is hidden in the checksumming function - and undone before returning to the caller. The IGMP and MLD query parsing functions in the bridge still assumed that the skb is pointing to the beginning of the IGMP/MLD message while it is now kept at the beginning of the IPv4/6 header. If there is a querier somewhere else, then this either causes the multicast snooping to stay disabled even though it could be enabled. Or, if we have the querier enabled too, then this can create unnecessary IGMP / MLD query messages on the link. Fixing this by taking the offset between IP and IGMP/MLD header into account, too. Fixes: 9afd85c9e455 ("net: Export IGMP/MLD message validation code") Reported-by: Simon Wunderlich Signed-off-by: Linus Lüssing Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'net/bridge') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 191ea66e4d92..6852f3c7009c 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1279,6 +1279,7 @@ static int br_ip4_multicast_query(struct net_bridge *br, struct br_ip saddr; unsigned long max_delay; unsigned long now = jiffies; + unsigned int offset = skb_transport_offset(skb); __be32 group; int err = 0; @@ -1289,14 +1290,14 @@ static int br_ip4_multicast_query(struct net_bridge *br, group = ih->group; - if (skb->len == sizeof(*ih)) { + if (skb->len == offset + sizeof(*ih)) { max_delay = ih->code * (HZ / IGMP_TIMER_SCALE); if (!max_delay) { max_delay = 10 * HZ; group = 0; } - } else if (skb->len >= sizeof(*ih3)) { + } else if (skb->len >= offset + sizeof(*ih3)) { ih3 = igmpv3_query_hdr(skb); if (ih3->nsrcs) goto out; @@ -1357,6 +1358,7 @@ static int br_ip6_multicast_query(struct net_bridge *br, struct br_ip saddr; unsigned long max_delay; unsigned long now = jiffies; + unsigned int offset = skb_transport_offset(skb); const struct in6_addr *group = NULL; bool is_general_query; int err = 0; @@ -1366,8 +1368,8 @@ static int br_ip6_multicast_query(struct net_bridge *br, (port && port->state == BR_STATE_DISABLED)) goto out; - if (skb->len == sizeof(*mld)) { - if (!pskb_may_pull(skb, sizeof(*mld))) { + if (skb->len == offset + sizeof(*mld)) { + if (!pskb_may_pull(skb, offset + sizeof(*mld))) { err = -EINVAL; goto out; } @@ -1376,7 +1378,7 @@ static int br_ip6_multicast_query(struct net_bridge *br, if (max_delay) group = &mld->mld_mca; } else { - if (!pskb_may_pull(skb, sizeof(*mld2q))) { + if (!pskb_may_pull(skb, offset + sizeof(*mld2q))) { err = -EINVAL; goto out; } -- cgit v1.2.3