linux-kernel - Re: Re: [PATCH] filemap: Init the newly allocated folio memory to 0 for the filemap

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: <20240801072454.GO5334@ZenIV>
Date: Thu, 1 Aug 2024 08:24:54 +0100
From: Al Viro <viro@...iv.linux.org.uk>
To: Lizhi Xu <lizhi.xu@...driver.com>
Cc: brauner@...nel.org, jack@...e.cz, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, phillip@...ashfs.org.uk,
	squashfs-devel@...ts.sourceforge.net,
	syzbot+24ac24ff58dc5b0d26b9@...kaller.appspotmail.com,
	syzkaller-bugs@...glegroups.com
Subject: Re: Re: [PATCH] filemap: Init the newly allocated folio memory to 0
 for the filemap

On Thu, Aug 01, 2024 at 08:10:16AM +0100, Al Viro wrote:

> Your patch is basically "fill the page with zeroes before reading anything
> into it".  It makes KMSAM warning STFU, but it does not fix anything
> in any of those cases.

Incidentally, it does that before it goes ahead and calls filemap_read_folio(),
with ->read_folio() as callback.  So if it does make it STFU, the case 1 (->read_folio()
not called at all) is out of running.  Would be interesting to see if that particular
->read_folio() is returning errors and if so - what errors are actually returned.