From 7f29405403d7c17f539c099987972b862e7e5255 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Wed, 23 Oct 2013 16:02:42 -0700 Subject: [PATCH] net: fix rtnl notification in atomic context commit 991fb3f74c "dev: always advertise rx_flags changes via netlink" introduced rtnl notification from __dev_set_promiscuity(), which can be called in atomic context. Steps to reproduce: ip tuntap add dev tap1 mode tap ifconfig tap1 up tcpdump -nei tap1 & ip tuntap del dev tap1 mode tap [ 271.627994] device tap1 left promiscuous mode [ 271.639897] BUG: sleeping function called from invalid context at mm/slub.c:940 [ 271.664491] in_atomic(): 1, irqs_disabled(): 0, pid: 3394, name: ip [ 271.677525] INFO: lockdep is turned off. [ 271.690503] CPU: 0 PID: 3394 Comm: ip Tainted: G W 3.12.0-rc3+ #73 [ 271.703996] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 271.731254] ffffffff81a58506 ffff8807f0d57a58 ffffffff817544e5 ffff88082fa0f428 [ 271.760261] ffff8808071f5f40 ffff8807f0d57a88 ffffffff8108bad1 ffffffff81110ff8 [ 271.790683] 0000000000000010 00000000000000d0 00000000000000d0 ffff8807f0d57af8 [ 271.822332] Call Trace: [ 271.838234] [] dump_stack+0x55/0x76 [ 271.854446] [] __might_sleep+0x181/0x240 [ 271.870836] [] ? rcu_irq_exit+0x68/0xb0 [ 271.887076] [] kmem_cache_alloc_node+0x4e/0x2a0 [ 271.903368] [] ? vprintk_emit+0x1dc/0x5a0 [ 271.919716] [] ? __alloc_skb+0x57/0x2a0 [ 271.936088] [] ? vprintk_emit+0x1e0/0x5a0 [ 271.952504] [] __alloc_skb+0x57/0x2a0 [ 271.968902] [] rtmsg_ifinfo+0x52/0x100 [ 271.985302] [] __dev_notify_flags+0xad/0xc0 [ 272.001642] [] __dev_set_promiscuity+0x8c/0x1c0 [ 272.017917] [] ? packet_notifier+0x5/0x380 [ 272.033961] [] dev_set_promiscuity+0x29/0x50 [ 272.049855] [] packet_dev_mc+0x87/0xc0 [ 272.065494] [] packet_notifier+0x1b2/0x380 [ 272.080915] [] ? packet_notifier+0x5/0x380 [ 272.096009] [] notifier_call_chain+0x66/0x150 [ 272.110803] [] __raw_notifier_call_chain+0xe/0x10 [ 272.125468] [] raw_notifier_call_chain+0x16/0x20 [ 272.139984] [] call_netdevice_notifiers_info+0x40/0x70 [ 272.154523] [] call_netdevice_notifiers+0x16/0x20 [ 272.168552] [] rollback_registered_many+0x145/0x240 [ 272.182263] [] rollback_registered+0x31/0x40 [ 272.195369] [] unregister_netdevice_queue+0x58/0x90 [ 272.208230] [] __tun_detach+0x140/0x340 [ 272.220686] [] tun_chr_close+0x36/0x60 Signed-off-by: Alexei Starovoitov Acked-by: Nicolas Dichtel Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 4 ++-- include/linux/rtnetlink.h | 2 +- net/core/dev.c | 16 ++++++++-------- net/core/rtnetlink.c | 9 +++++---- 4 files changed, 16 insertions(+), 15 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 2daa066..a141f40 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1213,7 +1213,7 @@ static int bond_master_upper_dev_link(struct net_device *bond_dev, if (err) return err; slave_dev->flags |= IFF_SLAVE; - rtmsg_ifinfo(RTM_NEWLINK, slave_dev, IFF_SLAVE); + rtmsg_ifinfo(RTM_NEWLINK, slave_dev, IFF_SLAVE, GFP_KERNEL); return 0; } @@ -1222,7 +1222,7 @@ static void bond_upper_dev_unlink(struct net_device *bond_dev, { netdev_upper_dev_unlink(slave_dev, bond_dev); slave_dev->flags &= ~IFF_SLAVE; - rtmsg_ifinfo(RTM_NEWLINK, slave_dev, IFF_SLAVE); + rtmsg_ifinfo(RTM_NEWLINK, slave_dev, IFF_SLAVE, GFP_KERNEL); } /* enslave device to bond device */ diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index f28544b..939428a 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -15,7 +15,7 @@ extern int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics); extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id, long expires, u32 error); -extern void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change); +void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change, gfp_t flags); /* RTNL is used as a global lock for all changes to network configuration */ extern void rtnl_lock(void); diff --git a/net/core/dev.c b/net/core/dev.c index bdffd65..0054c8c 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1203,7 +1203,7 @@ void netdev_state_change(struct net_device *dev) { if (dev->flags & IFF_UP) { call_netdevice_notifiers(NETDEV_CHANGE, dev); - rtmsg_ifinfo(RTM_NEWLINK, dev, 0); + rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL); } } EXPORT_SYMBOL(netdev_state_change); @@ -1293,7 +1293,7 @@ int dev_open(struct net_device *dev) if (ret < 0) return ret; - rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING); + rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL); call_netdevice_notifiers(NETDEV_UP, dev); return ret; @@ -1371,7 +1371,7 @@ static int dev_close_many(struct list_head *head) __dev_close_many(head); list_for_each_entry_safe(dev, tmp, head, close_list) { - rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING); + rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL); call_netdevice_notifiers(NETDEV_DOWN, dev); list_del_init(&dev->close_list); } @@ -5258,7 +5258,7 @@ void __dev_notify_flags(struct net_device *dev, unsigned int old_flags, unsigned int changes = dev->flags ^ old_flags; if (gchanges) - rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges); + rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC); if (changes & IFF_UP) { if (dev->flags & IFF_UP) @@ -5490,7 +5490,7 @@ static void rollback_registered_many(struct list_head *head) if (!dev->rtnl_link_ops || dev->rtnl_link_state == RTNL_LINK_INITIALIZED) - rtmsg_ifinfo(RTM_DELLINK, dev, ~0U); + rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL); /* * Flush the unicast and multicast chains @@ -5889,7 +5889,7 @@ int register_netdevice(struct net_device *dev) */ if (!dev->rtnl_link_ops || dev->rtnl_link_state == RTNL_LINK_INITIALIZED) - rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); + rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL); out: return ret; @@ -6501,7 +6501,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char call_netdevice_notifiers(NETDEV_UNREGISTER, dev); rcu_barrier(); call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev); - rtmsg_ifinfo(RTM_DELLINK, dev, ~0U); + rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL); /* * Flush the unicast and multicast chains @@ -6540,7 +6540,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char * Prevent userspace races by waiting until the network * device is fully setup before sending notifications. */ - rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); + rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL); synchronize_net(); err = 0; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 4aedf03..cf67144 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1984,14 +1984,15 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) return skb->len; } -void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change) +void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change, + gfp_t flags) { struct net *net = dev_net(dev); struct sk_buff *skb; int err = -ENOBUFS; size_t if_info_size; - skb = nlmsg_new((if_info_size = if_nlmsg_size(dev, 0)), GFP_KERNEL); + skb = nlmsg_new((if_info_size = if_nlmsg_size(dev, 0)), flags); if (skb == NULL) goto errout; @@ -2002,7 +2003,7 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change) kfree_skb(skb); goto errout; } - rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL); + rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, flags); return; errout: if (err < 0) @@ -2716,7 +2717,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi case NETDEV_JOIN: break; default: - rtmsg_ifinfo(RTM_NEWLINK, dev, 0); + rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL); break; } return NOTIFY_DONE; -- 2.7.4