linux-kernel - Re: [PATCH][CFT] [coredump] don't use __kernel_write() on kmap_local

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: <CA+icZUVXvMM-sK41oz_Ne4HyRGxXHNz=fPqy+1AYXmXPiE_=Rw@mail.gmail.com>
Date:   Tue, 4 Oct 2022 08:18:39 +0200
From:   Sedat Dilek <sedat.dilek@...il.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Al Viro <viro@...iv.linux.org.uk>,
        "J. R. Okajima" <hooanon05g@...il.com>,
        Ira Weiny <ira.weiny@...el.com>, linux-kernel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org,
        Geert Uytterhoeven <geert@...ux-m68k.org>
Subject: Re: [PATCH][CFT] [coredump] don't use __kernel_write() on kmap_local_page()

On Tue, Oct 4, 2022 at 2:51 AM Linus Torvalds
<torvalds@...ux-foundation.org> wrote:
>
> On Mon, Oct 3, 2022 at 4:37 PM Al Viro <viro@...iv.linux.org.uk> wrote:
> >
> > One variant would be to revert the original patch, put its
> > (hopefully) fixed variant into -next and let it sit there for
> > a while.  Another is to put this incremental into -next and
> > merge it into mainline once it gets a sane amount of testing.
>
> Just do the incremental fix. It looks obvious enough ("oops, we need
> to get the pos _after_ we've done any skip-lseeks on the core file")
> that I think it would be just harder to follow a "revert and follow up
> with a fix".
>
> I don't think it needs a ton of extra testing, with Okajima having
> already confirmed it fixes his problem case..
>
>                 Linus

[ CC Geert ]

There was another patch from Geert concerning the same coredump changes:

[PATCH] coredump: Move dump_emit_page() to kill unused warning

If CONFIG_ELF_CORE is not set:

    fs/coredump.c:835:12: error: ‘dump_emit_page’ defined but not used
[-Werror=unused-function]
      835 | static int dump_emit_page(struct coredump_params *cprm,
struct page *page)
          |            ^~~~~~~~~~~~~~

Fix this by moving dump_emit_page() inside the existing section
protected by #ifdef CONFIG_ELF_CORE.

Fixes: 06bbaa6dc53cb720 ("[coredump] don't use __kernel_write() on
kmap_local_page()")
Signed-off-by: Geert Uytterhoeven <geert@...ux-m68k.org>

Please, check yourself!

Best regards,
-Sedat-

[1] https://lore.kernel.org/all/20221003090657.2053236-1-geert@linux-m68k.org/