• Eric Dumazet's avatar
    netns: fix net_alloc_generic() · 073862ba
    Eric Dumazet authored
    When a new net namespace is created, we should attach to it a "struct
    net_generic" with enough slots (even empty), or we can hit the following
    BUG_ON() :
    
    [  200.752016] kernel BUG at include/net/netns/generic.h:40!
    ...
    [  200.752016]  [<ffffffff825c3cea>] ? get_cfcnfg+0x3a/0x180
    [  200.752016]  [<ffffffff821cf0b0>] ? lockdep_rtnl_is_held+0x10/0x20
    [  200.752016]  [<ffffffff825c41be>] caif_device_notify+0x2e/0x530
    [  200.752016]  [<ffffffff810d61b7>] notifier_call_chain+0x67/0x110
    [  200.752016]  [<ffffffff810d67c1>] raw_notifier_call_chain+0x11/0x20
    [  200.752016]  [<ffffffff821bae82>] call_netdevice_notifiers+0x32/0x60
    [  200.752016]  [<ffffffff821c2b26>] register_netdevice+0x196/0x300
    [  200.752016]  [<ffffffff821c2ca9>] register_netdev+0x19/0x30
    [  200.752016]  [<ffffffff81c1c67a>] loopback_net_init+0x4a/0xa0
    [  200.752016]  [<ffffffff821b5e62>] ops_init+0x42/0x180
    [  200.752016]  [<ffffffff821b600b>] setup_net+0x6b/0x100
    [  200.752016]  [<ffffffff821b6466>] copy_net_ns+0x86/0x110
    [  200.752016]  [<ffffffff810d5789>] create_new_namespaces+0xd9/0x190
    
    net_alloc_generic() should take into account the maximum index into the
    ptr array, as a subsystem might use net_generic() anytime.
    
    This also reduces number of reallocations in net_assign_generic()
    Reported-by: default avatarSasha Levin <levinsasha928@gmail.com>
    Tested-by: default avatarSasha Levin <levinsasha928@gmail.com>
    Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
    Cc: Sjur Brændeland <sjur.brandeland@stericsson.com>
    Cc: Eric W. Biederman <ebiederm@xmission.com>
    Cc: Pavel Emelyanov <xemul@openvz.org>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    073862ba
net_namespace.c 14.5 KB