When a net device is put administratively up, its 'IFF_UP' flag is set
(if not set already) and a 'NETDEV_UP' notification is emitted, which
causes the 8021q driver to add VLAN ID 0 on the device. The reverse
happens when a net device is put administratively down.
When changing the type of a bond to Ethernet, its 'IFF_UP' flag is
incorrectly cleared, resulting in the kernel skipping the above process
and VLAN ID 0 being leaked [1].
Fix by restoring the flag when changing the type to Ethernet, in a
similar fashion to the restoration of the 'IFF_SLAVE' flag.
The issue can be reproduced using the script in [2], with example out
before and after the fix in [3].
[1]
unreferenced object 0xffff888103479900 (size 256):
comm "ip", pid 329, jiffies 4294775225 (age 28.561s)
hex dump (first 32 bytes):
00 a0 0c 15 81 88 ff ff 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81a6051a>] kmalloc_trace+0x2a/0xe0
[<ffffffff8406426c>] vlan_vid_add+0x30c/0x790
[<ffffffff84068e21>] vlan_device_event+0x1491/0x21a0
[<ffffffff81440c8e>] notifier_call_chain+0xbe/0x1f0
[<ffffffff8372383a>] call_netdevice_notifiers_info+0xba/0x150
[<ffffffff837590f2>] __dev_notify_flags+0x132/0x2e0
[<ffffffff8375ad9f>] dev_change_flags+0x11f/0x180
[<ffffffff8379af36>] do_setlink+0xb96/0x4060
[<ffffffff837adf6a>] __rtnl_newlink+0xc0a/0x18a0
[<ffffffff837aec6c>] rtnl_newlink+0x6c/0xa0
[<ffffffff837ac64e>] rtnetlink_rcv_msg+0x43e/0xe00
[<ffffffff839a99e0>] netlink_rcv_skb+0x170/0x440
[<ffffffff839a738f>] netlink_unicast+0x53f/0x810
[<ffffffff839a7fcb>] netlink_sendmsg+0x96b/0xe90
[<ffffffff8369d12f>] ____sys_sendmsg+0x30f/0xa70
[<ffffffff836a6d7a>] ___sys_sendmsg+0x13a/0x1e0
unreferenced object 0xffff88810f6a83e0 (size 32):
comm "ip", pid 329, jiffies 4294775225 (age 28.561s)
hex dump (first 32 bytes):
a0 99 47 03 81 88 ff ff a0 99 47 03 81 88 ff ff ..G.......G.....
81 00 00 00 01 00 00 00 cc cc cc cc cc cc cc cc ................
backtrace:
[<ffffffff81a6051a>] kmalloc_trace+0x2a/0xe0
[<ffffffff84064369>] vlan_vid_add+0x409/0x790
[<ffffffff84068e21>] vlan_device_event+0x1491/0x21a0
[<ffffffff81440c8e>] notifier_call_chain+0xbe/0x1f0
[<ffffffff8372383a>] call_netdevice_notifiers_info+0xba/0x150
[<ffffffff837590f2>] __dev_notify_flags+0x132/0x2e0
[<ffffffff8375ad9f>] dev_change_flags+0x11f/0x180
[<ffffffff8379af36>] do_setlink+0xb96/0x4060
[<ffffffff837adf6a>] __rtnl_newlink+0xc0a/0x18a0
[<ffffffff837aec6c>] rtnl_newlink+0x6c/0xa0
[<ffffffff837ac64e>] rtnetlink_rcv_msg+0x43e/0xe00
[<ffffffff839a99e0>] netlink_rcv_skb+0x170/0x440
[<ffffffff839a738f>] netlink_unicast+0x53f/0x810
[<ffffffff839a7fcb>] netlink_sendmsg+0x96b/0xe90
[<ffffffff8369d12f>] ____sys_sendmsg+0x30f/0xa70
[<ffffffff836a6d7a>] ___sys_sendmsg+0x13a/0x1e0
[2]
ip link add name t-nlmon type nlmon
ip link add name t-dummy type dummy
ip link add name t-bond type bond mode active-backup
ip link set dev t-bond up
ip link set dev t-nlmon master t-bond
ip link set dev t-nlmon nomaster
ip link show dev t-bond
ip link set dev t-dummy master t-bond
ip link show dev t-bond
ip link del dev t-bond
ip link del dev t-dummy
ip link del dev t-nlmon
[3]
Before:
12: t-bond: <NO-CARRIER,BROADCAST,MULTICAST,MASTER,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
link/netlink
12: t-bond: <BROADCAST,MULTICAST,MASTER,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
link/ether 46:57:39:a4:46:a2 brd ff:ff:ff:ff:ff:ff
After:
12: t-bond: <NO-CARRIER,BROADCAST,MULTICAST,MASTER,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
link/netlink
12: t-bond: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
link/ether 66:48:7b:74:b6:8a brd ff:ff:ff:ff:ff:ff
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.