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authorEric Dumazet <edumazet@google.com>2018-07-31 06:30:54 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-08-06 16:20:47 +0200
commitdc8edd08cd894a87b0136c7f077b48290eef14f6 (patch)
tree9616e7e0c2b4a85966b19edd223ec3524b704886
parentdeaacd62c2175c624a41c1b3c721e23c660031e1 (diff)
bonding: avoid lockdep confusion in bond_get_stats()
[ Upstream commit 7e2556e40026a1b0c16f37446ab398d5a5a892e4 ] syzbot found that the following sequence produces a LOCKDEP splat [1] ip link add bond10 type bond ip link add bond11 type bond ip link set bond11 master bond10 To fix this, we can use the already provided nest_level. This patch also provides correct nesting for dev->addr_list_lock [1] WARNING: possible recursive locking detected 4.18.0-rc6+ #167 Not tainted -------------------------------------------- syz-executor751/4439 is trying to acquire lock: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline] (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426 but task is already holding lock: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline] (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&bond->stats_lock)->rlock); lock(&(&bond->stats_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor751/4439: #0: (____ptrval____) (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 #1: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: spin_lock include/linux/spinlock.h:310 [inline] #1: (____ptrval____) (&(&bond->stats_lock)->rlock){+.+.}, at: bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426 #2: (____ptrval____) (rcu_read_lock){....}, at: bond_get_stats+0x0/0x560 include/linux/compiler.h:215 stack backtrace: CPU: 0 PID: 4439 Comm: syz-executor751 Not tainted 4.18.0-rc6+ #167 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:1765 [inline] check_deadlock kernel/locking/lockdep.c:1809 [inline] validate_chain kernel/locking/lockdep.c:2405 [inline] __lock_acquire.cold.64+0x1fb/0x486 kernel/locking/lockdep.c:3435 lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:310 [inline] bond_get_stats+0xb4/0x560 drivers/net/bonding/bond_main.c:3426 dev_get_stats+0x10f/0x470 net/core/dev.c:8316 bond_get_stats+0x232/0x560 drivers/net/bonding/bond_main.c:3432 dev_get_stats+0x10f/0x470 net/core/dev.c:8316 rtnl_fill_stats+0x4d/0xac0 net/core/rtnetlink.c:1169 rtnl_fill_ifinfo+0x1aa6/0x3fb0 net/core/rtnetlink.c:1611 rtmsg_ifinfo_build_skb+0xc8/0x190 net/core/rtnetlink.c:3268 rtmsg_ifinfo_event.part.30+0x45/0xe0 net/core/rtnetlink.c:3300 rtmsg_ifinfo_event net/core/rtnetlink.c:3297 [inline] rtnetlink_event+0x144/0x170 net/core/rtnetlink.c:4716 notifier_call_chain+0x180/0x390 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1735 call_netdevice_notifiers net/core/dev.c:1753 [inline] netdev_features_change net/core/dev.c:1321 [inline] netdev_change_features+0xb3/0x110 net/core/dev.c:7759 bond_compute_features.isra.47+0x585/0xa50 drivers/net/bonding/bond_main.c:1120 bond_enslave+0x1b25/0x5da0 drivers/net/bonding/bond_main.c:1755 bond_do_ioctl+0x7cb/0xae0 drivers/net/bonding/bond_main.c:3528 dev_ifsioc+0x43c/0xb30 net/core/dev_ioctl.c:327 dev_ioctl+0x1b5/0xcc0 net/core/dev_ioctl.c:493 sock_do_ioctl+0x1d3/0x3e0 net/socket.c:992 sock_ioctl+0x30d/0x680 net/socket.c:1093 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440859 Code: e8 2c af 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc51a92878 EFLAGS: 00000213 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440859 RDX: 0000000020000040 RSI: 0000000000008990 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000022d5880 R11: 0000000000000213 R12: 0000000000007390 R13: 0000000000401db0 R14: 0000000000000000 R15: 0000000000000000 Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jay Vosburgh <j.vosburgh@gmail.com> Cc: Veaceslav Falico <vfalico@gmail.com> Cc: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/net/bonding/bond_main.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 00245b73c224..15aedb64a02b 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1687,6 +1687,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
goto err_upper_unlink;
}
+ bond->nest_level = dev_get_nest_level(bond_dev) + 1;
+
/* If the mode uses primary, then the following is handled by
* bond_change_active_slave().
*/
@@ -1734,7 +1736,6 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
if (bond_mode_uses_xmit_hash(bond))
bond_update_slave_arr(bond, NULL);
- bond->nest_level = dev_get_nest_level(bond_dev);
netdev_info(bond_dev, "Enslaving %s as %s interface with %s link\n",
slave_dev->name,
@@ -3379,6 +3380,13 @@ static void bond_fold_stats(struct rtnl_link_stats64 *_res,
}
}
+static int bond_get_nest_level(struct net_device *bond_dev)
+{
+ struct bonding *bond = netdev_priv(bond_dev);
+
+ return bond->nest_level;
+}
+
static void bond_get_stats(struct net_device *bond_dev,
struct rtnl_link_stats64 *stats)
{
@@ -3387,7 +3395,7 @@ static void bond_get_stats(struct net_device *bond_dev,
struct list_head *iter;
struct slave *slave;
- spin_lock(&bond->stats_lock);
+ spin_lock_nested(&bond->stats_lock, bond_get_nest_level(bond_dev));
memcpy(stats, &bond->bond_stats, sizeof(*stats));
rcu_read_lock();
@@ -4182,6 +4190,7 @@ static const struct net_device_ops bond_netdev_ops = {
.ndo_neigh_setup = bond_neigh_setup,
.ndo_vlan_rx_add_vid = bond_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = bond_vlan_rx_kill_vid,
+ .ndo_get_lock_subclass = bond_get_nest_level,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_netpoll_setup = bond_netpoll_setup,
.ndo_netpoll_cleanup = bond_netpoll_cleanup,
@@ -4680,6 +4689,7 @@ static int bond_init(struct net_device *bond_dev)
if (!bond->wq)
return -ENOMEM;
+ bond->nest_level = SINGLE_DEPTH_NESTING;
netdev_lockdep_set_classes(bond_dev);
list_add_tail(&bond->bond_list, &bn->dev_list);