2017-12-19 10:56:32

by Ortwin Glück

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Subject: dst refcount is -1

Hi,

On 4.14.6 I just got this (on a busy firewall):
[Tue Dec 19 11:15:59 2017] dst_release: dst:ffff9bb7aca0d6c0 refcnt:-1

Are you sure the refcounting is now correct?

Ortwin


2017-12-19 18:09:13

by Wei Wang

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Subject: Re: dst refcount is -1

On Tue, Dec 19, 2017 at 2:56 AM, Ortwin Glück <[email protected]> wrote:
> Hi,
>
> On 4.14.6 I just got this (on a busy firewall):
> [Tue Dec 19 11:15:59 2017] dst_release: dst:ffff9bb7aca0d6c0 refcnt:-1
>
> Are you sure the refcounting is now correct?
>
> Ortwin

Would you give more details under what circumstances it happened?
What kind of traffic is running? IPv4? IPv6? Or Both? Do you use xfrm?

2017-12-19 20:03:06

by Ortwin Glück

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Subject: Re: dst refcount is -1

On 12/19/2017 07:09 PM, Wei Wang wrote:
> Would you give more details under what circumstances it happened?

Circumstances are unknown as I can't correlate that log line to anything else.
If I have to guess, then it has to do with ipsec events. These tunnel tend to go
up and down a lot and there is steady traffic on most of them.

> What kind of traffic is running? IPv4? IPv6? Or Both? Do you use xfrm?

The machine has 10 IPv4 interfaces (via usb) and runs about 30 ipsec VPNs with
total maybe 200 tunnels (xfrm). No real IPv6 traffic, just the usual link-local
stuff that you see on any network.

Ortwin

2018-01-03 21:14:21

by Ortwin Glück

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Subject: Re: dst refcount is -1

Possibly this recent patch in master fixes it:
d2950278d2 (xfrm: put policies when reusing pcpu xdst entry)