* Kernel BUG on network namespace deletion
@ 2024-01-15 13:59 Марк Коренберг
2024-01-19 0:49 ` Jakub Kicinski
0 siblings, 1 reply; 6+ messages in thread
From: Марк Коренберг @ 2024-01-15 13:59 UTC (permalink / raw)
To: netdev
Kernel 6.6.9-200.fc39.x86_64
The following bash script demonstrates the problem (run under root):
```
#!/bin/bash
set -e -u -x
# Some cleanups
ip netns delete myspace || :
ip link del qweqwe1 || :
# The bug happens only with physical interfaces, not with, say, dummy one
ip link property add dev enp0s20f0u2 altname myname
ip netns add myspace
ip link set enp0s20f0u2 netns myspace
# add dummy interface + set the same altname as in background namespace.
ip link add name qweqwe1 type dummy
ip link property add dev qweqwe1 altname myname
# Trigger the bug. The kernel will try to return ethernet interface
# back to root namespace, but it can not, because of conflicting
# altnames.
ip netns delete myspace
# now `ip link` will hang forever !!!!!
```
I think, the problem is obvious. Although I don't know how to fix.
Remove conflicting altnames for interfaces that returns from killed
namespaces ?
On kernel 6.3.8 (at least) was another bug, that allows duplicate
altnames, and it was fixed mainline somewhere. I have another script
to trigger the bug on these old kernels. I did not bisect.
````
[ 494.473906] default_device_exit_net: failed to move enp0s20f0u2 to
init_net: -17
[ 494.473926] ------------[ cut here ]------------
[ 494.473927] kernel BUG at net/core/dev.c:11520!
[ 494.473932] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 494.473935] CPU: 3 PID: 3852 Comm: kworker/u32:17 Not tainted
6.6.9-200.fc39.x86_64 #1
[ 494.473938] Workqueue: netns cleanup_net
[ 494.473944] RIP: 0010:default_device_exit_batch+0x295/0x2a0
```
--
Segmentation fault
^ permalink raw reply [flat|nested] 6+ messages in thread
* kernel BUG on network namespace deletion
@ 2024-01-15 7:19 Марк Коренберг
2024-01-15 8:25 ` Greg KH
0 siblings, 1 reply; 6+ messages in thread
From: Марк Коренберг @ 2024-01-15 7:19 UTC (permalink / raw)
To: stable
Kernel 6.6.9-200.fc39.x86_64
The following bash script demonstrates the problem (run under root):
```
#!/bin/bash
set -e -u -x
# Some cleanups
ip netns delete myspace || :
ip link del qweqwe1 || :
# The bug happens only with physical interfaces, not with, say, dummy one
ip link property add dev enp0s20f0u2 altname myname
ip netns add myspace
ip link set enp0s20f0u2 netns myspace
# add dummy interface + set the same altname as in background namespace.
ip link add name qweqwe1 type dummy
ip link property add dev qweqwe1 altname myname
# Trigger the bug. The kernel will try to return ethernet interface
back to root namespace, but it can not, because of conflicting
altnames.
ip netns delete myspace
# now `ip link` will hang forever !!!!!
```
I think, the problem is obvious. Althougn I don't know how to fix.
Remove conflicting altnames for interfaces that returns from killed
namespaces ?
On kernel 6.3.8 (at least) was another bug, that allows dulicate
altnames, and it was fixed mainline somewhere. I have another script
to trigger the bug on these old kernels. I did not bisect.
````
[ 494.473906] default_device_exit_net: failed to move enp0s20f0u2 to
init_net: -17
[ 494.473926] ------------[ cut here ]------------
[ 494.473927] kernel BUG at net/core/dev.c:11520!
[ 494.473932] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 494.473935] CPU: 3 PID: 3852 Comm: kworker/u32:17 Not tainted
6.6.9-200.fc39.x86_64 #1
[ 494.473938] Workqueue: netns cleanup_net
[ 494.473944] RIP: 0010:default_device_exit_batch+0x295/0x2a0
```
--
Segmentation fault
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG on network namespace deletion
2024-01-15 7:19 kernel " Марк Коренберг
@ 2024-01-15 8:25 ` Greg KH
2024-01-15 10:00 ` Марк Коренберг
0 siblings, 1 reply; 6+ messages in thread
From: Greg KH @ 2024-01-15 8:25 UTC (permalink / raw)
To: Марк
Коренберг
Cc: stable
On Mon, Jan 15, 2024 at 12:19:06PM +0500, Марк Коренберг wrote:
> Kernel 6.6.9-200.fc39.x86_64
>
> The following bash script demonstrates the problem (run under root):
>
> ```
> #!/bin/bash
>
> set -e -u -x
>
> # Some cleanups
> ip netns delete myspace || :
> ip link del qweqwe1 || :
>
> # The bug happens only with physical interfaces, not with, say, dummy one
> ip link property add dev enp0s20f0u2 altname myname
> ip netns add myspace
> ip link set enp0s20f0u2 netns myspace
>
> # add dummy interface + set the same altname as in background namespace.
> ip link add name qweqwe1 type dummy
> ip link property add dev qweqwe1 altname myname
>
> # Trigger the bug. The kernel will try to return ethernet interface
> back to root namespace, but it can not, because of conflicting
> altnames.
> ip netns delete myspace
>
> # now `ip link` will hang forever !!!!!
> ```
>
> I think, the problem is obvious. Althougn I don't know how to fix.
> Remove conflicting altnames for interfaces that returns from killed
> namespaces ?
As this can only be triggered by root, not much for us to do here,
perhaps discuss it on the netdev mailing list for all network developers
to work on?
> On kernel 6.3.8 (at least) was another bug, that allows dulicate
> altnames, and it was fixed mainline somewhere. I have another script
> to trigger the bug on these old kernels. I did not bisect.
If this is an issue on 6.1.y, that would be good to know so that we can
try to fix the issue there if bisection can find it. Care to share the
script so that I can test?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG on network namespace deletion
2024-01-15 8:25 ` Greg KH
@ 2024-01-15 10:00 ` Марк Коренберг
2024-01-15 12:01 ` Greg KH
0 siblings, 1 reply; 6+ messages in thread
From: Марк Коренберг @ 2024-01-15 10:00 UTC (permalink / raw)
To: netdev; +Cc: stable, Greg KH
Hi, netdev. I have found a bug in the Linux Kernel. Please take a look.
пн, 15 янв. 2024 г. в 13:25, Greg KH <gregkh@linuxfoundation.org>:
>
> On Mon, Jan 15, 2024 at 12:19:06PM +0500, Марк Коренберг wrote:
> > Kernel 6.6.9-200.fc39.x86_64
> >
> > The following bash script demonstrates the problem (run under root):
> >
> > ```
> > #!/bin/bash
> >
> > set -e -u -x
> >
> > # Some cleanups
> > ip netns delete myspace || :
> > ip link del qweqwe1 || :
> >
> > # The bug happens only with physical interfaces, not with, say, dummy one
> > ip link property add dev enp0s20f0u2 altname myname
> > ip netns add myspace
> > ip link set enp0s20f0u2 netns myspace
> >
> > # add dummy interface + set the same altname as in background namespace.
> > ip link add name qweqwe1 type dummy
> > ip link property add dev qweqwe1 altname myname
> >
> > # Trigger the bug. The kernel will try to return ethernet interface
> > back to root namespace, but it can not, because of conflicting
> > altnames.
> > ip netns delete myspace
> >
> > # now `ip link` will hang forever !!!!!
> > ```
> >
> > I think, the problem is obvious. Althougn I don't know how to fix.
> > Remove conflicting altnames for interfaces that returns from killed
> > namespaces ?
>
> As this can only be triggered by root, not much for us to do here,
> perhaps discuss it on the netdev mailing list for all network developers
> to work on?
>
> > On kernel 6.3.8 (at least) was another bug, that allows dulicate
> > altnames, and it was fixed mainline somewhere. I have another script
> > to trigger the bug on these old kernels. I did not bisect.
>
> If this is an issue on 6.1.y, that would be good to know so that we can
> try to fix the issue there if bisection can find it. Care to share the
> script so that I can test?
>
> thanks,
>
> greg k-h
--
Segmentation fault
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG on network namespace deletion
2024-01-15 10:00 ` Марк Коренберг
@ 2024-01-15 12:01 ` Greg KH
0 siblings, 0 replies; 6+ messages in thread
From: Greg KH @ 2024-01-15 12:01 UTC (permalink / raw)
To: Марк
Коренберг
Cc: netdev, stable
On Mon, Jan 15, 2024 at 03:00:36PM +0500, Марк Коренберг wrote:
> Hi, netdev. I have found a bug in the Linux Kernel. Please take a look.
That's not a good way to post, sorry. Also what does this have to do
with stable@?
Please resend your original message to netdev, top-posting doesn't go
very well here, as per the email guidelines in our documentation :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-01-19 0:49 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2024-01-15 13:59 Kernel BUG on network namespace deletion Марк Коренберг
2024-01-19 0:49 ` Jakub Kicinski
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2024-01-15 7:19 kernel " Марк Коренберг
2024-01-15 8:25 ` Greg KH
2024-01-15 10:00 ` Марк Коренберг
2024-01-15 12:01 ` Greg KH
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