Commit Graph

253 Commits

Author SHA1 Message Date
Taehee Yoo
4dee15b4fd macvlan: fix null dereference in macvlan_device_event()
In the macvlan_device_event(), the list_first_entry_or_null() is used.
This function could return null pointer if there is no node.
But, the macvlan module doesn't check the null pointer.
So, null-ptr-deref would occur.

      bond0
        |
   +----+-----+
   |          |
macvlan0   macvlan1
   |          |
 dummy0     dummy1

The problem scenario.
If dummy1 is removed,
1. ->dellink() of dummy1 is called.
2. NETDEV_UNREGISTER of dummy1 notification is sent to macvlan module.
3. ->dellink() of macvlan1 is called.
4. NETDEV_UNREGISTER of macvlan1 notification is sent to bond module.
5. __bond_release_one() is called and it internally calls
   dev_set_mac_address().
6. dev_set_mac_address() calls the ->ndo_set_mac_address() of macvlan1,
   which is macvlan_set_mac_address().
7. macvlan_set_mac_address() calls the dev_set_mac_address() with dummy1.
8. NETDEV_CHANGEADDR of dummy1 is sent to macvlan module.
9. In the macvlan_device_event(), it calls list_first_entry_or_null().
At this point, dummy1 and macvlan1 were removed.
So, list_first_entry_or_null() will return NULL.

Test commands:
    ip netns add nst
    ip netns exec nst ip link add bond0 type bond
    for i in {0..10}
    do
        ip netns exec nst ip link add dummy$i type dummy
	ip netns exec nst ip link add macvlan$i link dummy$i \
		type macvlan mode passthru
	ip netns exec nst ip link set macvlan$i master bond0
    done
    ip netns del nst

Splat looks like:
[   40.585687][  T146] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP DEI
[   40.587249][  T146] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[   40.588342][  T146] CPU: 1 PID: 146 Comm: kworker/u8:2 Not tainted 5.7.0-rc1+ #532
[   40.589299][  T146] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   40.590469][  T146] Workqueue: netns cleanup_net
[   40.591045][  T146] RIP: 0010:macvlan_device_event+0x4e2/0x900 [macvlan]
[   40.591905][  T146] Code: 00 00 00 00 00 fc ff df 80 3c 06 00 0f 85 45 02 00 00 48 89 da 48 b8 00 00 00 00 00 fc ff d2
[   40.594126][  T146] RSP: 0018:ffff88806116f4a0 EFLAGS: 00010246
[   40.594783][  T146] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   40.595653][  T146] RDX: 0000000000000000 RSI: ffff88806547ddd8 RDI: ffff8880540f1360
[   40.596495][  T146] RBP: ffff88804011a808 R08: fffffbfff4fb8421 R09: fffffbfff4fb8421
[   40.597377][  T146] R10: ffffffffa7dc2107 R11: 0000000000000000 R12: 0000000000000008
[   40.598186][  T146] R13: ffff88804011a000 R14: ffff8880540f1000 R15: 1ffff1100c22de9a
[   40.599012][  T146] FS:  0000000000000000(0000) GS:ffff888067800000(0000) knlGS:0000000000000000
[   40.600004][  T146] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   40.600665][  T146] CR2: 00005572d3a807b8 CR3: 000000005fcf4003 CR4: 00000000000606e0
[   40.601485][  T146] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   40.602461][  T146] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   40.603443][  T146] Call Trace:
[   40.603871][  T146]  ? nf_tables_dump_setelem+0xa0/0xa0 [nf_tables]
[   40.604587][  T146]  ? macvlan_uninit+0x100/0x100 [macvlan]
[   40.605212][  T146]  ? __module_text_address+0x13/0x140
[   40.605842][  T146]  notifier_call_chain+0x90/0x160
[   40.606477][  T146]  dev_set_mac_address+0x28e/0x3f0
[   40.607117][  T146]  ? netdev_notify_peers+0xc0/0xc0
[   40.607762][  T146]  ? __module_text_address+0x13/0x140
[   40.608440][  T146]  ? notifier_call_chain+0x90/0x160
[   40.609097][  T146]  ? dev_set_mac_address+0x1f0/0x3f0
[   40.609758][  T146]  dev_set_mac_address+0x1f0/0x3f0
[   40.610402][  T146]  ? __local_bh_enable_ip+0xe9/0x1b0
[   40.611071][  T146]  ? bond_hw_addr_flush+0x77/0x100 [bonding]
[   40.611823][  T146]  ? netdev_notify_peers+0xc0/0xc0
[   40.612461][  T146]  ? bond_hw_addr_flush+0x77/0x100 [bonding]
[   40.613213][  T146]  ? bond_hw_addr_flush+0x77/0x100 [bonding]
[   40.613963][  T146]  ? __local_bh_enable_ip+0xe9/0x1b0
[   40.614631][  T146]  ? bond_time_in_interval.isra.31+0x90/0x90 [bonding]
[   40.615484][  T146]  ? __bond_release_one+0x9f0/0x12c0 [bonding]
[   40.616230][  T146]  __bond_release_one+0x9f0/0x12c0 [bonding]
[   40.616949][  T146]  ? bond_enslave+0x47c0/0x47c0 [bonding]
[   40.617642][  T146]  ? lock_downgrade+0x730/0x730
[   40.618218][  T146]  ? check_flags.part.42+0x450/0x450
[   40.618850][  T146]  ? __mutex_unlock_slowpath+0xd0/0x670
[   40.619519][  T146]  ? trace_hardirqs_on+0x30/0x180
[   40.620117][  T146]  ? wait_for_completion+0x250/0x250
[   40.620754][  T146]  bond_netdev_event+0x822/0x970 [bonding]
[   40.621460][  T146]  ? __module_text_address+0x13/0x140
[   40.622097][  T146]  notifier_call_chain+0x90/0x160
[   40.622806][  T146]  rollback_registered_many+0x660/0xcf0
[   40.623522][  T146]  ? netif_set_real_num_tx_queues+0x780/0x780
[   40.624290][  T146]  ? notifier_call_chain+0x90/0x160
[   40.624957][  T146]  ? netdev_upper_dev_unlink+0x114/0x180
[   40.625686][  T146]  ? __netdev_adjacent_dev_unlink_neighbour+0x30/0x30
[   40.626421][  T146]  ? mutex_is_locked+0x13/0x50
[   40.627016][  T146]  ? unregister_netdevice_queue+0xf2/0x240
[   40.627663][  T146]  unregister_netdevice_many.part.134+0x13/0x1b0
[   40.628362][  T146]  default_device_exit_batch+0x2d9/0x390
[   40.628987][  T146]  ? unregister_netdevice_many+0x40/0x40
[   40.629615][  T146]  ? dev_change_net_namespace+0xcb0/0xcb0
[   40.630279][  T146]  ? prepare_to_wait_exclusive+0x2e0/0x2e0
[   40.630943][  T146]  ? ops_exit_list.isra.9+0x97/0x140
[   40.631554][  T146]  cleanup_net+0x441/0x890
[ ... ]

Fixes: e289fd2817 ("macvlan: fix the problem when mac address changes for passthru mode")
Reported-by: syzbot+5035b1f9dc7ea4558d5a@syzkaller.appspotmail.com
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-21 15:51:55 -07:00
Mahesh Bandewar
ce9a4186f9 macvlan: add cond_resched() during multicast processing
The Rx bound multicast packets are deferred to a workqueue and
macvlan can also suffer from the same attack that was discovered
by Syzbot for IPvlan. This solution is not as effective as in
IPvlan. IPvlan defers all (Tx and Rx) multicast packet processing
to a workqueue while macvlan does this way only for the Rx. This
fix should address the Rx codition to certain extent.

Tx is still suseptible. Tx multicast processing happens when
.ndo_start_xmit is called, hence we cannot add cond_resched().
However, it's not that severe since the user which is generating
 / flooding will be affected the most.

Fixes: 412ca1550c ("macvlan: Move broadcasts into a work queue")
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-09 18:02:19 -07:00
David S. Miller
b3f7e3f23a Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
Eric Dumazet
1712b2fff8 macvlan: use skb_reset_mac_header() in macvlan_queue_xmit()
I missed the fact that macvlan_broadcast() can be used both
in RX and TX.

skb_eth_hdr() makes only sense in TX paths, so we can not
use it blindly in macvlan_broadcast()

Fixes: 96cc4b6958 ("macvlan: do not assume mac_header is set in macvlan_broadcast()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jurgen Van Ham <juvanham@gmail.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-16 13:12:37 +01:00
David S. Miller
a2d6d7ae59 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The ungrafting from PRIO bug fixes in net, when merged into net-next,
merge cleanly but create a build failure.  The resolution used here is
from Petr Machata.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09 12:13:43 -08:00
Eric Dumazet
96cc4b6958 macvlan: do not assume mac_header is set in macvlan_broadcast()
Use of eth_hdr() in tx path is error prone.

Many drivers call skb_reset_mac_header() before using it,
but others do not.

Commit 6d1ccff627 ("net: reset mac header in dev_start_xmit()")
attempted to fix this generically, but commit d346a3fae3
("packet: introduce PACKET_QDISC_BYPASS socket option") brought
back the macvlan bug.

Lets add a new helper, so that tx paths no longer have
to call skb_reset_mac_header() only to get a pointer
to skb->data.

Hopefully we will be able to revert 6d1ccff627
("net: reset mac header in dev_start_xmit()") and save few cycles
in transmit fast path.

BUG: KASAN: use-after-free in __get_unaligned_cpu32 include/linux/unaligned/packed_struct.h:19 [inline]
BUG: KASAN: use-after-free in mc_hash drivers/net/macvlan.c:251 [inline]
BUG: KASAN: use-after-free in macvlan_broadcast+0x547/0x620 drivers/net/macvlan.c:277
Read of size 4 at addr ffff8880a4932401 by task syz-executor947/9579

CPU: 0 PID: 9579 Comm: syz-executor947 Not tainted 5.5.0-rc4-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:145
 __get_unaligned_cpu32 include/linux/unaligned/packed_struct.h:19 [inline]
 mc_hash drivers/net/macvlan.c:251 [inline]
 macvlan_broadcast+0x547/0x620 drivers/net/macvlan.c:277
 macvlan_queue_xmit drivers/net/macvlan.c:520 [inline]
 macvlan_start_xmit+0x402/0x77f drivers/net/macvlan.c:559
 __netdev_start_xmit include/linux/netdevice.h:4447 [inline]
 netdev_start_xmit include/linux/netdevice.h:4461 [inline]
 dev_direct_xmit+0x419/0x630 net/core/dev.c:4079
 packet_direct_xmit+0x1a9/0x250 net/packet/af_packet.c:240
 packet_snd net/packet/af_packet.c:2966 [inline]
 packet_sendmsg+0x260d/0x6220 net/packet/af_packet.c:2991
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:659
 __sys_sendto+0x262/0x380 net/socket.c:1985
 __do_sys_sendto net/socket.c:1997 [inline]
 __se_sys_sendto net/socket.c:1993 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1993
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442639
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 5b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc13549e08 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000442639
RDX: 000000000000000e RSI: 0000000020000080 RDI: 0000000000000003
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000403bb0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 9389:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:561 [inline]
 tomoyo_realpath_from_path+0xc5/0x660 security/tomoyo/realpath.c:252
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822
 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129
 security_inode_getattr+0xf2/0x150 security/security.c:1222
 vfs_getattr+0x25/0x70 fs/stat.c:115
 vfs_statx_fd+0x71/0xc0 fs/stat.c:145
 vfs_fstat include/linux/fs.h:3265 [inline]
 __do_sys_newfstat+0x9b/0x120 fs/stat.c:378
 __se_sys_newfstat fs/stat.c:375 [inline]
 __x64_sys_newfstat+0x54/0x80 fs/stat.c:375
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9389:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 tomoyo_realpath_from_path+0x1a7/0x660 security/tomoyo/realpath.c:289
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822
 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129
 security_inode_getattr+0xf2/0x150 security/security.c:1222
 vfs_getattr+0x25/0x70 fs/stat.c:115
 vfs_statx_fd+0x71/0xc0 fs/stat.c:145
 vfs_fstat include/linux/fs.h:3265 [inline]
 __do_sys_newfstat+0x9b/0x120 fs/stat.c:378
 __se_sys_newfstat fs/stat.c:375 [inline]
 __x64_sys_newfstat+0x54/0x80 fs/stat.c:375
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a4932000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1025 bytes inside of
 4096-byte region [ffff8880a4932000, ffff8880a4933000)
The buggy address belongs to the page:
page:ffffea0002924c80 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0
raw: 00fffe0000010200 ffffea0002846208 ffffea00028f3888 ffff8880aa402000
raw: 0000000000000000 ffff8880a4932000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a4932300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a4932380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880a4932400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880a4932480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a4932500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: b863ceb7dd ("[NET]: Add macvlan driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 12:52:33 -08:00
Richard Cochran
d25de984aa net: macvlan: Use the PHY time stamping interface.
The macvlan layer tests fields of the phy_device in order to determine
whether to invoke the PHY's tsinfo ethtool callback.  This patch
replaces the open coded logic with an invocation of the proper
methods.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-25 19:51:33 -08:00
Menglong Dong
1d7ea55668 macvlan: schedule bc_work even if error
While enqueueing a broadcast skb to port->bc_queue, schedule_work()
is called to add port->bc_work, which processes the skbs in
bc_queue, to "events" work queue. If port->bc_queue is full, the
skb will be discarded and schedule_work(&port->bc_work) won't be
called. However, if port->bc_queue is full and port->bc_work is not
running or pending, port->bc_queue will keep full and schedule_work()
won't be called any more, and all broadcast skbs to macvlan will be
discarded. This case can happen:

macvlan_process_broadcast() is the pending function of port->bc_work,
it moves all the skbs in port->bc_queue to the queue "list", and
processes the skbs in "list". During this, new skbs will keep being
added to port->bc_queue in macvlan_broadcast_enqueue(), and
port->bc_queue may already full when macvlan_process_broadcast()
return. This may happen, especially when there are a lot of real-time
threads and the process is preempted.

Fix this by calling schedule_work(&port->bc_work) even if
port->bc_work is full in macvlan_broadcast_enqueue().

Fixes: 412ca1550c ("macvlan: Move broadcasts into a work queue")
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-25 10:54:22 -08:00
Taehee Yoo
f3b0a18bb6 net: remove unnecessary variables and callback
This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, ->ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes ->ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:49 -07:00
Taehee Yoo
ab92d68fc2 net: core: add generic lockdep keys
Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:48 -07:00
David S. Miller
a6cdeeb16b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07 11:00:14 -07:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Gustavo A. R. Silva
36f18439ea macvlan: Replace strncpy() by strscpy()
The strncpy() function is being deprecated. Replace it by the safer
strscpy() and fix the following Coverity warning:

"Calling strncpy with a maximum size argument of 16 bytes on destination
array ifrr.ifr_ifrn.ifrn_name of size 16 bytes might leave the destination
string unterminated."

Notice that, unlike strncpy(), strscpy() always null-terminates the
destination string.

Addresses-Coverity-ID: 1445537 ("Buffer not null terminated")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-29 00:00:01 -07:00
Gustavo A. R. Silva
02596252db macvlan: Mark expected switch fall-through
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warning:

drivers/net/macvlan.c: In function ‘macvlan_do_ioctl’:
drivers/net/macvlan.c:839:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (!net_eq(dev_net(dev), &init_net))
      ^
drivers/net/macvlan.c:841:2: note: here
  case SIOCGHWTSTAMP:
  ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-20 11:37:41 -07:00
Hangbin Liu
6c2ea9ebaf macvlan: disable SIOCSHWTSTAMP in container
Miroslav pointed that with NET_ADMIN enabled in container, a normal user
could be mapped to root and is able to change the real device's rx
filter via ioctl on macvlan, which would affect the other ptp process on
host. Fix it by disabling SIOCSHWTSTAMP in container.

Fixes: 254c0a2bfe ("macvlan: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to real device")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-09 09:30:35 -07:00
Michal Kubecek
ae0be8de9a netlink: make nla_nest_start() add NLA_F_NESTED flag
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:03:44 -04:00
Hangbin Liu
254c0a2bfe macvlan: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to real device
Similiar to commit a6111d3c93 ("vlan: Pass SIOC[SG]HWTSTAMP ioctls to
real device") and commit 37dd9255b2 ("vlan: Pass ethtool get_ts_info
queries to real device."), add MACVlan HW ptp support.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-20 11:04:41 -07:00
Andy Roulin
2e8b4ba646 macvlan: add ndo_change_proto_down support
Add ndo_change_proto_down support through dev_change_proto_down_generic
for use by control protocols like VRRPD.

Signed-off-by: Andy Roulin <aroulin@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-24 13:01:04 -08:00
Julian Wiedmann
913564fbc2 macvlan: use netif_is_macvlan_port()
Replace the macvlan_port_exists() macro with its twin from netdevice.h

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-31 09:26:31 -08:00
David S. Miller
fa7f3a8d56 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Completely minor snmp doc conflict.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-21 14:41:32 -08:00
Yang Wei
bf97403ac4 macvlan: replace kfree_skb by consume_skb for drop profiles
Replace the kfree_skb() by consume_skb() to be drop monitor(dropwatch,
perf) friendly.

Signed-off-by: Yang Wei <yang.wei9@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-17 22:09:09 -08:00
Petr Machata
87b0984ebf net: Add extack argument to ndo_fdb_add()
Drivers may not be able to support certain FDB entries, and an error
code is insufficient to give clear hints as to the reasons of rejection.

In order to make it possible to communicate the rejection reason, extend
ndo_fdb_add() with an extack argument. Adapt the existing
implementations of ndo_fdb_add() to take the parameter (and ignore it).
Pass the extack parameter when invoking ndo_fdb_add() from rtnl_fdb_add().

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-17 15:18:47 -08:00
Petr Machata
3a37a9636c net: dev: Add extack argument to dev_set_mac_address()
A follow-up patch will add a notifier type NETDEV_PRE_CHANGEADDR, which
allows vetoing of MAC address changes. One prominent path to that
notification is through dev_set_mac_address(). Therefore give this
function an extack argument, so that it can be packed together with the
notification. Thus a textual reason for rejection (or a warning) can be
communicated back to the user.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 18:41:38 -08:00
Matteo Croce
59f997b088 macvlan: return correct error value
A MAC address must be unique among all the macvlan devices with the same
lower device. The only exception is the passthru [sic] mode,
which shares the lower device address.

When duplicate addresses are detected, EBUSY is returned when bringing
the interface up:

    # ip link add macvlan0 link eth0 type macvlan
    # read addr </sys/class/net/eth0/address
    # ip link set macvlan0 address $addr
    # ip link set macvlan0 up
    RTNETLINK answers: Device or resource busy

Use correct error code which is EADDRINUSE, and do the check also
earlier, on address change:

    # ip link set macvlan0 address $addr
    RTNETLINK answers: Address already in use

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-03 16:02:43 -08:00
Debabrata Banerjee
c9fbd71f73 netpoll: allow cleanup to be synchronous
This fixes a problem introduced by:
commit 2cde6acd49 ("netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock")

When using netconsole on a bond, __netpoll_cleanup can asynchronously
recurse multiple times, each __netpoll_free_async call can result in
more __netpoll_free_async's. This means there is now a race between
cleanup_work queues on multiple netpoll_info's on multiple devices and
the configuration of a new netpoll. For example if a netconsole is set
to enable 0, reconfigured, and enable 1 immediately, this netconsole
will likely not work.

Given the reason for __netpoll_free_async is it can be called when rtnl
is not locked, if it is locked, we should be able to execute
synchronously. It appears to be locked everywhere it's called from.

Generalize the design pattern from the teaming driver for current
callers of __netpoll_free_async.

CC: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-19 17:01:43 -07:00
Travis Brown
80fd2d6ca5 macvlan: Change status when lower device goes down
Today macvlan ignores the notification when a lower device goes
administratively down, preventing the lack of connectivity from
bubbling up.

Processing NETDEV_DOWN results in a macvlan state of LOWERLAYERDOWN
with NO-CARRIER which should be easy to interpret in userspace.

2: lower: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
3: macvlan@lower: <NO-CARRIER,BROADCAST,MULTICAST,UP,M-DOWN> mtu 1500 qdisc noqueue state LOWERLAYERDOWN mode DEFAULT group default qlen 1000

Signed-off-by: Suresh Krishnan <skrishnan@arista.com>
Signed-off-by: Travis Brown <travisb@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-11 23:07:22 -07:00
Alexander Duyck
eadec877ce net: Add support for subordinate traffic classes to netdev_pick_tx
This change makes it so that we can support the concept of subordinate
device traffic classes to the core networking code. In doing this we can
start pulling out the driver specific bits needed to support selecting a
queue based on an upper device.

The solution at is currently stands is only partially implemented. I have
the start of some XPS bits in here, but I would still need to allow for
configuration of the XPS maps on the queues reserved for the subordinate
devices. For now I am using the reference to the sb_dev XPS map as just a
way to skip the lookup of the lower device XPS map for now as that would
result in the wrong queue being picked.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2018-07-09 12:53:58 -07:00
Alexander Duyck
81d4e91cd5 macvlan: Use software path for offloaded local, broadcast, and multicast traffic
This change makes it so that we use a software path for packets that are
going to be locally switched between two macvlan interfaces on the same
device. In addition we resort to software replication of broadcast and
multicast packets instead of offloading that to hardware.

The general idea is that using the device for east/west traffic local to
the system is extremely inefficient. We can only support up to whatever the
PCIe limit is for any given device so this caps us at somewhere around 20G
for devices supported by ixgbe. This is compounded even further when you
take broadcast and multicast into account as a single 10G port can come to
a crawl as a packet is replicated up to 60+ times in some cases. In order
to get away from that I am implementing changes so that we handle
broadcast/multicast replication and east/west local traffic all in
software.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2018-04-25 08:26:19 -07:00
Alexander Duyck
7d775f6347 macvlan: Rename fwd_priv to accel_priv and add accessor function
This change renames the fwd_priv member to accel_priv as this more
accurately reflects the actual purpose of this value. In addition I am
adding an accessor which will allow us to further abstract this in the
future if needed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2018-04-25 08:26:19 -07:00
Shannon Nelson
13fbcc8dc5 macvlan: filter out unsupported feature flags
Adding a macvlan device on top of a lowerdev that supports
the xfrm offloads fails with a new regression:
  # ip link add link ens1f0 mv0 type macvlan
  RTNETLINK answers: Operation not permitted

Tracing down the failure shows that the macvlan device inherits
the NETIF_F_HW_ESP and NETIF_F_HW_ESP_TX_CSUM feature flags
from the lowerdev, but with no dev->xfrmdev_ops API filled
in, it doesn't actually support xfrm.  When the request is
made to add the new macvlan device, the XFRM listener for
NETDEV_REGISTER calls xfrm_api_check() which fails the new
registration because dev->xfrmdev_ops is NULL.

The macvlan creation succeeds when we filter out the ESP
feature flags in macvlan_fix_features(), so let's filter them
out like we're already filtering out ~NETIF_F_NETNS_LOCAL.
When XFRM support is added in the future, we can add the flags
into MACVLAN_FEATURES.

This same problem could crop up in the future with any other
new feature flags, so let's filter out any flags that aren't
defined as supported in macvlan.

Fixes: d77e38e612 ("xfrm: Add an IPsec hardware offloading API")
Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-11 22:46:16 -04:00
Alexey Kodanev
4e14bf4236 macvlan: fix use-after-free in macvlan_common_newlink()
The following use-after-free was reported by KASan when running
LTP macvtap01 test on 4.16-rc2:

[10642.528443] BUG: KASAN: use-after-free in
               macvlan_common_newlink+0x12ef/0x14a0 [macvlan]
[10642.626607] Read of size 8 at addr ffff880ba49f2100 by task ip/18450
...
[10642.963873] Call Trace:
[10642.994352]  dump_stack+0x5c/0x7c
[10643.035325]  print_address_description+0x75/0x290
[10643.092938]  kasan_report+0x28d/0x390
[10643.137971]  ? macvlan_common_newlink+0x12ef/0x14a0 [macvlan]
[10643.207963]  macvlan_common_newlink+0x12ef/0x14a0 [macvlan]
[10643.275978]  macvtap_newlink+0x171/0x260 [macvtap]
[10643.334532]  rtnl_newlink+0xd4f/0x1300
...
[10646.256176] Allocated by task 18450:
[10646.299964]  kasan_kmalloc+0xa6/0xd0
[10646.343746]  kmem_cache_alloc_trace+0xf1/0x210
[10646.397826]  macvlan_common_newlink+0x6de/0x14a0 [macvlan]
[10646.464386]  macvtap_newlink+0x171/0x260 [macvtap]
[10646.522728]  rtnl_newlink+0xd4f/0x1300
...
[10647.022028] Freed by task 18450:
[10647.061549]  __kasan_slab_free+0x138/0x180
[10647.111468]  kfree+0x9e/0x1c0
[10647.147869]  macvlan_port_destroy+0x3db/0x650 [macvlan]
[10647.211411]  rollback_registered_many+0x5b9/0xb10
[10647.268715]  rollback_registered+0xd9/0x190
[10647.319675]  register_netdevice+0x8eb/0xc70
[10647.370635]  macvlan_common_newlink+0xe58/0x14a0 [macvlan]
[10647.437195]  macvtap_newlink+0x171/0x260 [macvtap]

Commit d02fd6e7d2 ("macvlan: Fix one possible double free") handles
the case when register_netdevice() invokes ndo_uninit() on error and
as a result free the port. But 'macvlan_port_get_rtnl(dev))' check
(returns dev->rx_handler_data), which was added by this commit in order
to prevent double free, is not quite correct:

* for macvlan it always returns NULL because 'lowerdev' is the one that
  was used to register rx handler (port) in macvlan_port_create() as
  well as to unregister it in macvlan_port_destroy().
* for macvtap it always returns a valid pointer because macvtap registers
  its own rx handler before macvlan_common_newlink().

Fixes: d02fd6e7d2 ("macvlan: Fix one possible double free")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-23 10:48:10 -05:00
Gao Feng
d02fd6e7d2 macvlan: Fix one possible double free
Because the macvlan_uninit would free the macvlan port, so there is one
double free case in macvlan_common_newlink. When the macvlan port is just
created, then register_netdevice or netdev_upper_dev_link failed and they
would invoke macvlan_uninit. Then it would reach the macvlan_port_destroy
which triggers the double free.

Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-02 13:30:14 -05:00
Alexander Duyck
56fd2b2ca4 macvlan/macvtap: Add support for L2 forwarding offloads with macvtap
This patch reverts earlier commit b13ba1b83f ("macvlan: forbid L2
fowarding offload for macvtap"). The reason for reverting this is because
the original patch no longer fixes what it previously did as the
underlying structure has changed for macvtap. Specifically macvtap
originally pulled packets directly off of the lowerdev. However in commit
6acf54f1cf ("macvtap: Add support of packet capture on macvtap device.")
that code was changed and instead macvtap would listen directly on the
macvtap device itself instead of the lower device. As such, the L2
forwarding offload should now be able to provide a performance advantage of
skipping the checks on the lower dev while not introducing any sort of
regression.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-19 12:43:59 +01:00
Alexander Duyck
c8c41ea1bd macvlan: Only update pkt_type if destination MAC address matches
This patch updates the pkt_type to PACKET_HOST only if the destination MAC
address matches on the on the source based macvlan. It didn't make sense to
be updating broadcast, multicast, and non-local destined frames with
PACKET_HOST.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-14 18:46:36 -07:00
Alexander Duyck
dd6b9c2c33 macvlan: Only deliver one copy of the frame to the macvlan interface
This patch intoduces a slight adjustment for macvlan to address the fact
that in source mode I was seeing two copies of any packet addressed to the
macvlan interface being delivered where there should have been only one.

The issue appears to be that one copy was delivered based on the source MAC
address and then the second copy was being delivered based on the
destination MAC address. To fix it I am just treating a unicast address
match as though it is not a match since source based macvlan isn't supposed
to be matching based on the destination MAC anyway.

Fixes: 79cf79abce ("macvlan: add source mode")
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-14 18:46:36 -07:00
David Ahern
42ab19ee90 net: Add extack to upper device linking
Add extack arg to netdev_upper_dev_link and netdev_master_upper_dev_link

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-04 21:39:33 -07:00
Zhang Shengju
07850a4f74 macvlan: code refine to check data before using
This patch checks data first at one place, return if it's null.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-20 13:46:45 -07:00
Dimitris Michailidis
f21e507701 macvlan: add offload features for encapsulation
Currently macvlan devices do not set their hw_enc_features making
encapsulated Tx packets resort to SW fallbacks. Add encapsulation GSO
offloads to ->features as is done for the other GSOs and set
->hw_enc_features.

Signed-off-by: Dimitris Michailidis <dmichail@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18 16:06:54 -07:00
David S. Miller
fb652fdfe8 macvlan/macvtap: Remove NETIF_F_UFO advertisement.
It is going away.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-17 09:52:57 -07:00
David S. Miller
b079115937 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
A set of overlapping changes in macvlan and the rocker
driver, nothing serious.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30 12:43:08 -04:00
Matthias Schiffer
a8b8a889e3 net: add netlink_ext_ack argument to rtnl_link_ops.validate
Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-26 23:13:22 -04:00
Matthias Schiffer
ad744b223c net: add netlink_ext_ack argument to rtnl_link_ops.changelink
Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-26 23:13:22 -04:00
Matthias Schiffer
7a3f4a1851 net: add netlink_ext_ack argument to rtnl_link_ops.newlink
Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-26 23:13:21 -04:00
Vlad Yasevich
18c8c54de9 macvlan: Let passthru macvlan correctly restore lower mac address
Passthru macvlans directly change the mac address of the lower
level device.  That's OK, but after the macvlan is deleted,
the lower device is left with changed address and one needs to
reboot to bring back the origina HW addresses.

This scenario is actually quite common with passthru macvtap devices.

This patch attempts to solve this, by storing the mac address
of the lower device in macvlan_port structure and keeping track of
it through the changes.

After this patch, any changes to the lower device mac address
done trough the macvlan device, will be reverted back.  Any
changs done directly to the lower device mac address will be kept.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22 11:17:42 -04:00
Vlad Yasevich
43c2d578a0 macvlan: convert port passthru to flags.
Convert the port passthru boolean into flags with accesor functions.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22 11:17:42 -04:00
Vlad Yasevich
e696cda7bd macvlan: Fix passthru macvlan mac address inheritance
When a lower device of the passthru macvlan changes it's address,
passthru macvlan is supposed to change it's own address as well.
However, that doesn't happen correctly because the check in
macvlan_addr_busy() will catch the fact that the lower level
(port) mac address is the same as the address we are trying to
assign to the macvlan, and return an error.  As a reasult,
the address of the passthru macvlan device is never changed.

The same thing happens when the user attempts to change the
mac address of the passthru macvlan.

The simple solution appers to be to not check against
the lower device in case of passthru macvlan device, since
the 2 addresses are _supposed_ to be the same.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22 11:17:41 -04:00
Vlad Yasevich
e26f43faa0 macvlan: Do not return error when setting the same mac address
The user currently gets an EBUSY error when attempting to set
the mac address on a macvlan device to the same value.

This should really be a no-op as nothing changes.  Catch
the condition and return early.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22 11:17:41 -04:00
David S. Miller
0ddead90b2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The conflicts were two cases of overlapping changes in
batman-adv and the qed driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15 11:59:32 -04:00
Zhang Shengju
a88e2676a6 macvlan: propagate the mac address change status for lowerdev
The macvlan dev should propagate the return value of mac address change for
lower device in the passthru mode, instead of always return 0.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 14:34:51 -04:00
David S. Miller
cf124db566 net: Fix inconsistent teardown and release of private netdev state.
Network devices can allocate reasources and private memory using
netdev_ops->ndo_init().  However, the release of these resources
can occur in one of two different places.

Either netdev_ops->ndo_uninit() or netdev->destructor().

The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.

netdev_ops->ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.

netdev->destructor(), on the other hand, does not run until the
netdev references all go away.

Further complicating the situation is that netdev->destructor()
almost universally does also a free_netdev().

This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.

If netdev_ops->ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops->ndo_uninit().  But
it is not able to invoke netdev->destructor().

This is because netdev->destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.

However, this means that the resources that would normally be released
by netdev->destructor() will not be.

Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.

Many drivers do not try to deal with this, and instead we have leaks.

Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev->destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().

netdev->priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev->destructor(), except for
free_netdev().

netdev->needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().

Now, register_netdevice() can sanely release all resources after
ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
and netdev->priv_destructor().

And at the end of unregister_netdevice(), we invoke
netdev->priv_destructor() and optionally call free_netdev().

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-07 15:53:24 -04:00