[6.1.y regresssion] 9a95ec9144ee ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") causes log spam on ping to unreachable host

[6.1.y regresssion] 9a95ec9144ee ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") causes log spam on ping to unreachable host

[Salvatore Bonaccorso]

Control: forwarded -1 https://lore.kernel.org/regressions/177771348699.1898023.16904466444228860838@eldamar.lan

Hi

[sending correctly including the needed mailinglists]

This is a 6.1.y specific regression, so I'm not CC'ing netdev, but
maintainers, hope this is fine. After a backport of 81b84de32bb2
("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") was
applied in the 6.1.y stable series as
9a95ec9144eeff1fc6fbcc21b677e322c6f1430b, user are reporting that on
pings to unreachable host the log is spammed with the "detected local
route for %pI4 during ICMP sending, src %pI4\n" messages.

One report is at: https://bugs.debian.org/1135514

This does not happens with other stable series versions (6.12.y
tested explicitly, 6.6.y I have not avaiable to test).

Is there a missing requisite in 6.1.y?

#regzbot introduced: 9a95ec9144eeff1fc6fbcc21b677e322c6f1430b
#regzbot link: https://bugs.debian.org/1135514

Regards,
Salvatore

Re: [6.1.y regresssion] 9a95ec9144ee ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") causes log spam on ping to unreachable host

[Jiayuan Chen]

I think it because we failed to backport  this patch before:
https://lore.kernel.org/stable/20250207161555-b1a8749027831a1a@stable.kernel.org/T/#m0c880c1f04f7211aea9b7f6b4de0b64aa1726417

On Sat, May 2, 2026 at 5:22 PM Salvatore Bonaccorso <carnil@debian.org> wrote:
>
> Control: forwarded -1 https://lore.kernel.org/regressions/177771348699.1898023.16904466444228860838@eldamar.lan
>
> Hi
>
> [sending correctly including the needed mailinglists]
>
> This is a 6.1.y specific regression, so I'm not CC'ing netdev, but
> maintainers, hope this is fine. After a backport of 81b84de32bb2
> ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") was
> applied in the 6.1.y stable series as
> 9a95ec9144eeff1fc6fbcc21b677e322c6f1430b, user are reporting that on
> pings to unreachable host the log is spammed with the "detected local
> route for %pI4 during ICMP sending, src %pI4\n" messages.
>
> One report is at: https://bugs.debian.org/1135514
>
> This does not happens with other stable series versions (6.12.y
> tested explicitly, 6.6.y I have not avaiable to test).
>
> Is there a missing requisite in 6.1.y?
>
> #regzbot introduced: 9a95ec9144eeff1fc6fbcc21b677e322c6f1430b
> #regzbot link: https://bugs.debian.org/1135514
>
> Regards,
> Salvatore

Re: Bug#1135514: [6.1.y regresssion] 9a95ec9144ee ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") causes log spam on ping to unreachable host

[Salvatore Bonaccorso]

Hi Jiayuan,

On Wed, May 06, 2026 at 09:04:24AM +0800, Jiayuan Chen wrote:
> I think it because we failed to backport  this patch before:
> https://lore.kernel.org/stable/20250207161555-b1a8749027831a1a@stable.kernel.org/T/#m0c880c1f04f7211aea9b7f6b4de0b64aa1726417

Which won't apply cleanly, I assume this was the reason it got not
backported to 6.1.y. Do you have a backport of that, or should the
original commit introducing the issue be reverted from 6.1.y?

Regards,
Salvtore

Re: Bug#1135514: [6.1.y regresssion] 9a95ec9144ee ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") causes log spam on ping to unreachable host

[Jiayuan Chen]

On Wed, May 6, 2026 at 5:39 PM Salvatore Bonaccorso <carnil@debian.org> wrote:
>
> Hi Jiayuan,
>
> On Wed, May 06, 2026 at 09:04:24AM +0800, Jiayuan Chen wrote:
> > I think it because we failed to backport  this patch before:
> > https://lore.kernel.org/stable/20250207161555-b1a8749027831a1a@stable.kernel.org/T/#m0c880c1f04f7211aea9b7f6b4de0b64aa1726417
>
> Which won't apply cleanly, I assume this was the reason it got not
> backported to 6.1.y. Do you have a backport of that, or should the
> original commit introducing the issue be reverted from 6.1.y?
>
> Regards,
> Salvtore

I tried to backport this patch to stable. Hope these patches apply successfully.

https://lore.kernel.org/stable/20260506012057.285743-1-jiayuan.chen@linux.dev/T/#u
https://lore.kernel.org/stable/20260506012115.286204-1-jiayuan.chen@linux.dev/T/#u

Re: Bug#1135514: [6.1.y regresssion] 9a95ec9144ee ("xfrm: fix ip_rt_bug race in icmp_route_lookup reverse path") causes log spam on ping to unreachable host

[Salvatore Bonaccorso]

Hi Jiayuan,

On Wed, May 06, 2026 at 05:47:52PM +0800, Jiayuan Chen wrote:
> On Wed, May 6, 2026 at 5:39 PM Salvatore Bonaccorso <carnil@debian.org> wrote:
> >
> > Hi Jiayuan,
> >
> > On Wed, May 06, 2026 at 09:04:24AM +0800, Jiayuan Chen wrote:
> > > I think it because we failed to backport  this patch before:
> > > https://lore.kernel.org/stable/20250207161555-b1a8749027831a1a@stable.kernel.org/T/#m0c880c1f04f7211aea9b7f6b4de0b64aa1726417
> >
> > Which won't apply cleanly, I assume this was the reason it got not
> > backported to 6.1.y. Do you have a backport of that, or should the
> > original commit introducing the issue be reverted from 6.1.y?
> >
> > Regards,
> > Salvtore
> 
> I tried to backport this patch to stable. Hope these patches apply successfully.
> 
> https://lore.kernel.org/stable/20260506012057.285743-1-jiayuan.chen@linux.dev/T/#u
> https://lore.kernel.org/stable/20260506012115.286204-1-jiayuan.chen@linux.dev/T/#u

I tried the patch on top of 6.1.170 and this resolves the issue. I
added the Tested-by to your patch submission.

Thank you.

Regards,
Salvatore