linux/drivers/net/bonding
Willem de Bruijn 001e465f09 bonding: update nest level on unlink
A network device stack with multiple layers of bonding devices can
trigger a false positive lockdep warning. Adding lockdep nest levels
fixes this. Update the level on both enslave and unlink, to avoid the
following series of events ..

    ip netns add test
    ip netns exec test bash
    ip link set dev lo addr 00:11:22:33:44:55
    ip link set dev lo down

    ip link add dev bond1 type bond
    ip link add dev bond2 type bond

    ip link set dev lo master bond1
    ip link set dev bond1 master bond2

    ip link set dev bond1 nomaster
    ip link set dev bond2 master bond1

.. from still generating a splat:

    [  193.652127] ======================================================
    [  193.658231] WARNING: possible circular locking dependency detected
    [  193.664350] 4.20.0 #8 Not tainted
    [  193.668310] ------------------------------------------------------
    [  193.674417] ip/15577 is trying to acquire lock:
    [  193.678897] 00000000a40e3b69 (&(&bond->stats_lock)->rlock#3/3){+.+.}, at: bond_get_stats+0x58/0x290
    [  193.687851]
    	       but task is already holding lock:
    [  193.693625] 00000000807b9d9f (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0x58/0x290

    [..]

    [  193.851092]        lock_acquire+0xa7/0x190
    [  193.855138]        _raw_spin_lock_nested+0x2d/0x40
    [  193.859878]        bond_get_stats+0x58/0x290
    [  193.864093]        dev_get_stats+0x5a/0xc0
    [  193.868140]        bond_get_stats+0x105/0x290
    [  193.872444]        dev_get_stats+0x5a/0xc0
    [  193.876493]        rtnl_fill_stats+0x40/0x130
    [  193.880797]        rtnl_fill_ifinfo+0x6c5/0xdc0
    [  193.885271]        rtmsg_ifinfo_build_skb+0x86/0xe0
    [  193.890091]        rtnetlink_event+0x5b/0xa0
    [  193.894320]        raw_notifier_call_chain+0x43/0x60
    [  193.899225]        netdev_change_features+0x50/0xa0
    [  193.904044]        bond_compute_features.isra.46+0x1ab/0x270
    [  193.909640]        bond_enslave+0x141d/0x15b0
    [  193.913946]        do_set_master+0x89/0xa0
    [  193.918016]        do_setlink+0x37c/0xda0
    [  193.921980]        __rtnl_newlink+0x499/0x890
    [  193.926281]        rtnl_newlink+0x48/0x70
    [  193.930238]        rtnetlink_rcv_msg+0x171/0x4b0
    [  193.934801]        netlink_rcv_skb+0xd1/0x110
    [  193.939103]        rtnetlink_rcv+0x15/0x20
    [  193.943151]        netlink_unicast+0x3b5/0x520
    [  193.947544]        netlink_sendmsg+0x2fd/0x3f0
    [  193.951942]        sock_sendmsg+0x38/0x50
    [  193.955899]        ___sys_sendmsg+0x2ba/0x2d0
    [  193.960205]        __x64_sys_sendmsg+0xad/0x100
    [  193.964687]        do_syscall_64+0x5a/0x460
    [  193.968823]        entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 7e2556e400 ("bonding: avoid lockdep confusion in bond_get_stats()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-10 16:49:39 -05:00
..
Makefile bonding: add sysfs /slave dir for bond slave devices. 2014-01-17 18:51:58 -08:00
bond_3ad.c bonding: fix indentation issues, remove extra spaces 2018-12-18 15:01:23 -08:00
bond_alb.c net: dev: Add extack argument to dev_set_mac_address() 2018-12-13 18:41:38 -08:00
bond_debugfs.c bonding: convert to DEFINE_SHOW_ATTRIBUTE 2018-12-10 12:05:20 -08:00
bond_main.c bonding: update nest level on unlink 2019-01-10 16:49:39 -05:00
bond_netlink.c bonding: fix length of actor system 2018-10-29 20:39:38 -07:00
bond_options.c bonding: set default miimon value for non-arp modes if not set 2018-07-21 10:26:21 -07:00
bond_procfs.c bonding: switch to proc_create_seq_data 2018-05-16 07:24:30 +02:00
bond_sysfs.c bonding: don't cast const buf in sysfs store 2018-07-22 10:09:30 -07:00
bond_sysfs_slave.c drivers/net: Use octal not symbolic permissions 2018-03-26 12:07:49 -04:00
bonding_priv.h net/bonding: Make DRV macros private 2015-04-26 22:59:53 -04:00