linux/net/ethtool
Antoine Tenart dde91ccfa2 ethtool: do not perform operations on net devices being unregistered
There is a short period between a net device starts to be unregistered
and when it is actually gone. In that time frame ethtool operations
could still be performed, which might end up in unwanted or undefined
behaviours[1].

Do not allow ethtool operations after a net device starts its
unregistration. This patch targets the netlink part as the ioctl one
isn't affected: the reference to the net device is taken and the
operation is executed within an rtnl lock section and the net device
won't be found after unregister.

[1] For example adding Tx queues after unregister ends up in NULL
    pointer exceptions and UaFs, such as:

      BUG: KASAN: use-after-free in kobject_get+0x14/0x90
      Read of size 1 at addr ffff88801961248c by task ethtool/755

      CPU: 0 PID: 755 Comm: ethtool Not tainted 5.15.0-rc6+ #778
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/014
      Call Trace:
       dump_stack_lvl+0x57/0x72
       print_address_description.constprop.0+0x1f/0x140
       kasan_report.cold+0x7f/0x11b
       kobject_get+0x14/0x90
       kobject_add_internal+0x3d1/0x450
       kobject_init_and_add+0xba/0xf0
       netdev_queue_update_kobjects+0xcf/0x200
       netif_set_real_num_tx_queues+0xb4/0x310
       veth_set_channels+0x1c3/0x550
       ethnl_set_channels+0x524/0x610

Fixes: 041b1c5d4a ("ethtool: helper functions for netlink interface")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20211203101318.435618-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-06 16:53:32 -08:00
..
bitset.c ethtool: fix stack overflow in ethnl_parse_bitset() 2020-12-09 15:50:38 -08:00
bitset.h ethtool: add ethnl_parse_bitset() helper 2020-03-12 15:32:32 -07:00
cabletest.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
channels.c ethtool: fix the check logic of at least one channel for RX/TX 2021-02-28 11:49:07 -08:00
coalesce.c ethtool: extend coalesce setting uAPI with CQE mode 2021-08-24 07:38:29 -07:00
common.c net: sock: extend SO_TIMESTAMPING for PHC binding 2021-07-01 13:08:18 -07:00
common.h net: ethtool: Export helpers for getting EEPROM info 2021-04-11 16:34:56 -07:00
debug.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
eee.c ethtool: fix incorrect datatype in set_eee ops 2021-04-06 16:42:25 -07:00
eeprom.c ethtool: Validate module EEPROM offset as part of policy 2021-06-22 10:40:54 -07:00
features.c ethtool: netlink: add missing netdev_features_change() call 2020-11-09 17:15:34 -08:00
fec.c ethtool: add FEC statistics 2021-04-15 17:08:29 -07:00
ioctl.c ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce() 2021-11-26 11:17:47 -08:00
linkinfo.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
linkmodes.c ethtool: Expose the number of lanes in use 2021-02-03 18:37:29 -08:00
linkstate.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
Makefile ethtool: Add ability to control transceiver modules' power mode 2021-10-06 17:47:49 -07:00
module.c ethtool: Add ability to control transceiver modules' power mode 2021-10-06 17:47:49 -07:00
netlink.c ethtool: do not perform operations on net devices being unregistered 2021-12-06 16:53:32 -08:00
netlink.h ethtool: Add ability to control transceiver modules' power mode 2021-10-06 17:47:49 -07:00
pause.c ethtool: fix ethtool msg len calculation for pause stats 2021-11-03 11:20:45 +00:00
phc_vclocks.c ethtool: add a new command for getting PHC virtual clocks 2021-07-01 13:08:18 -07:00
privflags.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
rings.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
stats.c ethtool: stats: Fix a copy-paste error 2021-05-19 11:57:33 -07:00
strset.c ethtool: strset: fix message length calculation 2021-06-14 12:14:24 -07:00
tsinfo.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
tunnels.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00
wol.c ethtool: link up ethnl_header_policy as a nested policy 2020-10-06 06:25:55 -07:00