linux-kernel - Re: [PATCH 05/14] uaccess: add generic __{get,put}_kernel

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: <CAK8P3a2+qG=Q9Si_2D7wjM7Qao2JCnYqKgU=W-SFwoG+fT-U3A@mail.gmail.com>
Date:   Tue, 15 Feb 2022 14:16:50 +0100
From:   Arnd Bergmann <arnd@...nel.org>
To:     Al Viro <viro@...iv.linux.org.uk>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Christoph Hellwig <hch@....de>,
        linux-arch <linux-arch@...r.kernel.org>,
        Linux-MM <linux-mm@...ck.org>,
        Linux API <linux-api@...r.kernel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Russell King - ARM Linux <linux@...linux.org.uk>,
        Will Deacon <will@...nel.org>, Guo Ren <guoren@...nel.org>,
        Brian Cain <bcain@...eaurora.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Michal Simek <monstr@...str.eu>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Nick Hu <nickhu@...estech.com>,
        Greentime Hu <green.hu@...il.com>,
        Dinh Nguyen <dinguyen@...nel.org>,
        Stafford Horne <shorne@...il.com>,
        Helge Deller <deller@....de>,
        Michael Ellerman <mpe@...erman.id.au>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Rich Felker <dalias@...c.org>,
        David Miller <davem@...emloft.net>,
        Richard Weinberger <richard@....at>,
        "the arch/x86 maintainers" <x86@...nel.org>,
        Max Filippov <jcmvbkbc@...il.com>,
        "Eric W . Biederman" <ebiederm@...ssion.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Ard Biesheuvel <ardb@...nel.org>,
        alpha <linux-alpha@...r.kernel.org>,
        "open list:SYNOPSYS ARC ARCHITECTURE" 
        <linux-snps-arc@...ts.infradead.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        linux-csky@...r.kernel.org,
        "open list:QUALCOMM HEXAGON..." <linux-hexagon@...r.kernel.org>,
        linux-ia64@...r.kernel.org,
        linux-m68k <linux-m68k@...ts.linux-m68k.org>,
        "open list:BROADCOM NVRAM DRIVER" <linux-mips@...r.kernel.org>,
        Openrisc <openrisc@...ts.librecores.org>,
        Parisc List <linux-parisc@...r.kernel.org>,
        linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>,
        linux-riscv <linux-riscv@...ts.infradead.org>,
        linux-s390 <linux-s390@...r.kernel.org>,
        Linux-sh list <linux-sh@...r.kernel.org>,
        sparclinux <sparclinux@...r.kernel.org>,
        linux-um <linux-um@...ts.infradead.org>,
        "open list:TENSILICA XTENSA PORT (xtensa)" 
        <linux-xtensa@...ux-xtensa.org>
Subject: Re: [PATCH 05/14] uaccess: add generic __{get,put}_kernel_nofault

On Tue, Feb 15, 2022 at 1:31 AM Al Viro <viro@...iv.linux.org.uk> wrote:
>
> On Mon, Feb 14, 2022 at 05:34:43PM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@...db.de>
> >
> > All architectures that don't provide __{get,put}_kernel_nofault() yet
> > can implement this on top of __{get,put}_user.
> >
> > Add a generic version that lets everything use the normal
> > copy_{from,to}_kernel_nofault() code based on these, removing the last
> > use of get_fs()/set_fs() from architecture-independent code.
>
> I'd put the list of those architectures (AFAICS, that's alpha, ia64,
> microblaze, nds32, nios2, openrisc, sh, sparc32, xtensa) into commit
> message - it's not that hard to find out, but...

done.

> And AFAICS, you've missed nios2 - see
> #define __put_user(x, ptr) put_user(x, ptr)
> in there.  nds32 oddities are dealt with earlier in the series, this
> one is not...

Ok, fixed my bug in nios2 __put_user() as well now. This one is not nearly
as bad as nds32, at least without my patches it should work as expected.

Unfortunately I also noticed that __get_user() on microblaze and nios2
is completely broken for 64-bit arguments, where these copy eight bytes
into a four byte buffer. I'll try to come up with a fix for this as well then.

         Arnd