From 06f6d1094aa0992432b1e2a0920b0ee86ccd83bf Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Wed, 15 Jul 2015 21:52:51 +0200 Subject: [PATCH] bonding: fix destruction of bond with devices different from arphrd_ether When the bonding is being unloaded and the netdevice notifier is unregistered it executes NETDEV_UNREGISTER for each device which should remove the bond's proc entry but if the device enslaved is not of ARPHRD_ETHER type and is in front of the bonding, it may execute bond_release_and_destroy() first which would release the last slave and destroy the bond device leaving the proc entry and thus we will get the following error (with dynamic debug on for bond_netdev_event to see the events order): [ 908.963051] eql: event: 9 [ 908.963052] eql: IFF_SLAVE [ 908.963054] eql: event: 2 [ 908.963056] eql: IFF_SLAVE [ 908.963058] eql: event: 6 [ 908.963059] eql: IFF_SLAVE [ 908.963110] bond0: Releasing active interface eql [ 908.976168] bond0: Destroying bond bond0 [ 908.976266] bond0 (unregistering): Released all slaves [ 908.984097] ------------[ cut here ]------------ [ 908.984107] WARNING: CPU: 0 PID: 1787 at fs/proc/generic.c:575 remove_proc_entry+0x112/0x160() [ 908.984110] remove_proc_entry: removing non-empty directory 'net/bonding', leaking at least 'bond0' [ 908.984111] Modules linked in: bonding(-) eql(O) 9p nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev qxl drm_kms_helper snd_hda_codec_generic aesni_intel ttm aes_x86_64 glue_helper pcspkr lrw gf128mul ablk_helper cryptd snd_hda_intel virtio_console snd_hda_codec psmouse serio_raw snd_hwdep snd_hda_core 9pnet_virtio 9pnet evdev joydev drm virtio_balloon snd_pcm snd_timer snd soundcore i2c_piix4 i2c_core pvpanic acpi_cpufreq parport_pc parport processor thermal_sys button autofs4 ext4 crc16 mbcache jbd2 hid_generic usbhid hid sg sr_mod cdrom ata_generic virtio_blk virtio_net floppy ata_piix e1000 libata ehci_pci virtio_pci scsi_mod uhci_hcd ehci_hcd virtio_ring virtio usbcore usb_common [last unloaded: bonding] [ 908.984168] CPU: 0 PID: 1787 Comm: rmmod Tainted: G W O 4.2.0-rc2+ #8 [ 908.984170] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 908.984172] 0000000000000000 ffffffff81732d41 ffffffff81525b34 ffff8800358dfda8 [ 908.984175] ffffffff8106c521 ffff88003595af78 ffff88003595af40 ffff88003e3a4280 [ 908.984178] ffffffffa058d040 0000000000000000 ffffffff8106c59a ffffffff8172ebd0 [ 908.984181] Call Trace: [ 908.984188] [] ? dump_stack+0x40/0x50 [ 908.984193] [] ? warn_slowpath_common+0x81/0xb0 [ 908.984196] [] ? warn_slowpath_fmt+0x4a/0x50 [ 908.984199] [] ? remove_proc_entry+0x112/0x160 [ 908.984205] [] ? bond_destroy_proc_dir+0x26/0x30 [bonding] [ 908.984208] [] ? bond_net_exit+0x8e/0xa0 [bonding] [ 908.984217] [] ? ops_exit_list.isra.4+0x37/0x70 [ 908.984225] [] ? unregister_pernet_operations+0x8d/0xd0 [ 908.984228] [] ? unregister_pernet_subsys+0x1d/0x30 [ 908.984232] [] ? bonding_exit+0x23/0xdba [bonding] [ 908.984236] [] ? SyS_delete_module+0x18a/0x250 [ 908.984241] [] ? task_work_run+0x89/0xc0 [ 908.984244] [] ? entry_SYSCALL_64_fastpath+0x16/0x75 [ 908.984247] ---[ end trace 7c006ed4abbef24b ]--- Thus remove the proc entry manually if bond_release_and_destroy() is used. Because of the checks in bond_remove_proc_entry() it's not a problem for a bond device to change namespaces (the bug fixed by the Fixes commit) but since commit f9399814927ad ("bonding: Don't allow bond devices to change network namespaces.") that can't happen anyway. Reported-by: Carol Soto Signed-off-by: Nikolay Aleksandrov Fixes: a64d49c3dd50 ("bonding: Manage /proc/net/bonding/ entries from the netdev events") Tested-by: Carol L Soto Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 317a49480475..ec1404ec4d2f 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1916,6 +1916,7 @@ static int bond_release_and_destroy(struct net_device *bond_dev, bond_dev->priv_flags |= IFF_DISABLE_NETPOLL; netdev_info(bond_dev, "Destroying bond %s\n", bond_dev->name); + bond_remove_proc_entry(bond); unregister_netdevice(bond_dev); } return ret; -- 2.34.1