Ido Schimmel 1fb22ed671 devlink: Fix warning when unregistering a port
When a devlink port is unregistered, its type is expected to be unset or
otherwise a WARNING is generated [1]. This was supposed to be handled by
cited commit by clearing the type upon 'NETDEV_PRE_UNINIT'.

The assumption was that no other events can be generated for the netdev
after this event, but this proved to be wrong. After the event is
generated, netdev_wait_allrefs_any() will rebroadcast a
'NETDEV_UNREGISTER' until the netdev's reference count drops to 1. This
causes devlink to set the port type back to Ethernet.

Fix by only setting and clearing the port type upon 'NETDEV_POST_INIT'
and 'NETDEV_PRE_UNINIT', respectively. For all other events, preserve
the port type.

[1]
WARNING: CPU: 0 PID: 11 at net/core/devlink.c:9998 devl_port_unregister+0x2f6/0x390 net/core/devlink.c:9998
Modules linked in:
CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.1.0-rc3-next-20221107-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: netns cleanup_net
RIP: 0010:devl_port_unregister+0x2f6/0x390 net/core/devlink.c:9998
[...]
Call Trace:
 <TASK>
 __nsim_dev_port_del+0x1bb/0x240 drivers/net/netdevsim/dev.c:1433
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1443 [inline]
 nsim_dev_reload_destroy+0x171/0x510 drivers/net/netdevsim/dev.c:1660
 nsim_dev_reload_down+0x6b/0xd0 drivers/net/netdevsim/dev.c:968
 devlink_reload+0x1c2/0x6b0 net/core/devlink.c:4501
 devlink_pernet_pre_exit+0x104/0x1c0 net/core/devlink.c:12609
 ops_pre_exit_list net/core/net_namespace.c:159 [inline]
 cleanup_net+0x451/0xb10 net/core/net_namespace.c:594
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Fixes: 02a68a47ea ("net: devlink: track netdev with devlink_port assigned")
Reported-by: syzbot+85e47e1a08b3e159b159@syzkaller.appspotmail.com
Reported-by: syzbot+c2ca18f0fccdd1f09c66@syzkaller.appspotmail.com
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20221110085150.520800-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-10 13:15:04 -08:00
2022-09-28 09:02:20 +02:00
2022-11-01 15:25:21 +01:00
2022-09-28 09:02:20 +02:00
2022-10-20 21:27:21 -07:00
2022-09-28 09:02:20 +02:00
2022-10-30 15:19:28 -07:00

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.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%