linux-kernel - Re: [PATCH] fs: touch up predicts in putname()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251102061443.GE2441659@ZenIV>
Date: Sun, 2 Nov 2025 06:14:43 +0000
From: Al Viro <viro@...iv.linux.org.uk>
To: Mateusz Guzik <mjguzik@...il.com>
Cc: brauner@...nel.org, jack@...e.cz, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] fs: touch up predicts in putname()

On Sat, Nov 01, 2025 at 09:19:21AM +0100, Mateusz Guzik wrote:
> On Sat, Nov 1, 2025 at 7:05 AM Al Viro <viro@...iv.linux.org.uk> wrote:
> >
> > On Fri, Oct 31, 2025 at 08:17:53PM +0000, Al Viro wrote:
> >
> > > 0) get rid of audit_reusename() and aname->uptr (I have that series,
> > > massaging it for posting at the moment).  Basically, don't have
> > > getname et.al. called in retry loops - there are few places doing
> > > that, and they are not hard to fix.
> >
> > See #work.filename-uptr; I'll post individual patches tomorrow morning,
> > hopefully along with getname_alien()/take_filename() followups, including
> > the removal of atomic (still not settled on the calling conventions for
> > getname_alien()).
> >
> 
> Ok, in that case I think it will be most expedient if my patch gets
> dropped and you just fold the updated predicts into your patchset
> somewhere. I don't need any credit.

See #work.filename-refcnt.  I'm not entirely happy about the API, if you
see a saner way to do it, I'd really like to hear it.  Stuff in the series:

	* get rid of getname in retry loops.  Only 9 places like that left,
massaged out of existence one by one.  (##1..9)
	* drop audit_reusename() and filename->uptr (#10)
	* get rid of mixing LOOKUP_EMPTY with the rest of the flags -
very few places do that at this point and they are not hard to take
care of (##11..15)
	* take LOOKUP_EMPTY out of LOOKUP_... space entirely - make it
GETNAME_EMPTY and have it passed only to getname_flags() (#16)
	* add GETNAME_NOAUDIT for "don't call audit_getname() there" (#17).
Helpers: getname_alien()/getname_uflags_alien() being wrappers for
that; io-uring switched to those for filename import (in ->prep()).
take_filename(): take a reference to struct filename, leaving NULL
behind, feed it to audit_getname() and return to caller.   Used by
io-uring ->issue() instances that feed an imported filename to
do_{mkdir,mknod...}() - the stuff that does actual work, done in the
thread that will do that work.
	* make filename->refcnt non-atomic; now it can be done (#19,
on top of merge from vfs-common/vfs-6.19.misc to bring your commit
in).