linux-kernel - Re: [PATCH 14/14] uaccess: drop set

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: <CAK8P3a1DPxgti+aRVUABQFZz-yT0KNU9QZpB9iGNCPkBHnv_xg@mail.gmail.com>
Date:   Tue, 15 Feb 2022 09:10:05 +0100
From:   Arnd Bergmann <arnd@...nel.org>
To:     Helge Deller <deller@....de>
Cc:     Al Viro <viro@...iv.linux.org.uk>,
        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>,
        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 14/14] uaccess: drop set_fs leftovers

On Tue, Feb 15, 2022 at 8:46 AM Helge Deller <deller@....de> wrote:
>
> On 2/15/22 04:03, Al Viro wrote:
> > On Mon, Feb 14, 2022 at 05:34:52PM +0100, Arnd Bergmann wrote:
> >> diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h
> >> index b5835325d44b..2f4a1b1ef387 100644
> >> --- a/arch/parisc/include/asm/futex.h
> >> +++ b/arch/parisc/include/asm/futex.h
> >> @@ -99,7 +99,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
> >>      /* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
> >>       * our gateway page, and causes no end of trouble...
> >>       */
> >> -    if (uaccess_kernel() && !uaddr)
> >> +    if (!uaddr)
> >>              return -EFAULT;
> >
> >       Huh?  uaccess_kernel() is removed since it becomes always false now,
> > so this looks odd.
> >
> >       AFAICS, the comment above that check refers to futex_detect_cmpxchg()
> > -> cmpxchg_futex_value_locked() -> futex_atomic_cmpxchg_inatomic() call chain.
> > Which had been gone since commit 3297481d688a (futex: Remove futex_cmpxchg
> > detection).  The comment *and* the check should've been killed off back
> > then.
> >       Let's make sure to get both now...
>
> Right. Arnd, can you drop this if() and the comment above it?

Done.

       Arnd