[OpenAFS] Strange DNS SRV traffic resulting from stat() in 1.8.13.2

[Ryan C. Underwood]

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On Tue, Aug 26, 2025 at 10:59:32AM -0400, Jeffrey Altman wrote:
> > The process was running on Ubuntu 24.04, kernel 6.14.0-28-generic, Open=
AFS Client 1.8.13.2-1ubuntu1.
>=20
> Ryan observes the behavior on 25.04 and you observe it on 24.04.  Both ru=
nning 6.14.0 based kernels. =20
>=20
> The bug was introduced to OpenAFS in commit 0306f3fdac736e15620f5802bdce5=
10d25bb2450 which must have been cherry-picked into the Ubuntu builds.
>=20
> struct qstr =E2=80=9Cquick string=E2=80=9D is a counted string not a NUL =
terminated string.   The mistake introduced in the aforementioned commit re=
sults in the full path being evaluated as the dentry name instead of just t=
he path component the dentry actually refers to.
>=20
> As a result, the d_revalidate() call will always fail, the current dentry=
 will always be invalidated, and a full lookup() will be performed each tim=
e a cached dentry is used.
>=20
> Marc Dionne should be credited with identifying the mistake.
>=20
> This mistake is not present in the AuriStorFS client.

Thanks Jeffrey, I am cc'ing the following people to raise awareness of
this critical bug

Christof Hanke <christof.hanke@mpcdf.mpg.de> who appears to have
pulled this commit into the OpenSUSE build for kernel 6.14
compatibility

Jacob Martin <jacob.martin@canonical.com> who did the same for Ubuntu:
https://lists.ubuntu.com/archives/plucky-changes/2025-March/014784.html

I filed the following Ubuntu bug report:
https://bugs.launchpad.net/ubuntu/+source/openafs/+bug/2121466

--=20
Ryan C. Underwood, <nemesis@icequake.net>

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