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 for Android: free password hash cracker in your pocket

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

Message-ID: <215c0ddc-54b1-bcb1-c5aa-bd17c6b100a8@gmx.de>
Date:   Tue, 15 Feb 2022 08:46:05 +0100
From:   Helge Deller <deller@....de>
To:     Al Viro <viro@...iv.linux.org.uk>, Arnd Bergmann <arnd@...nel.org>
Cc:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Christoph Hellwig <hch@....de>, linux-arch@...r.kernel.org,
        linux-mm@...ck.org, linux-api@...r.kernel.org, arnd@...db.de,
        linux-kernel@...r.kernel.org, linux@...linux.org.uk,
        will@...nel.org, guoren@...nel.org, bcain@...eaurora.org,
        geert@...ux-m68k.org, monstr@...str.eu, tsbogend@...ha.franken.de,
        nickhu@...estech.com, green.hu@...il.com, dinguyen@...nel.org,
        shorne@...il.com, mpe@...erman.id.au, peterz@...radead.org,
        mingo@...hat.com, mark.rutland@....com, hca@...ux.ibm.com,
        dalias@...c.org, davem@...emloft.net, richard@....at,
        x86@...nel.org, jcmvbkbc@...il.com, ebiederm@...ssion.com,
        akpm@...ux-foundation.org, ardb@...nel.org,
        linux-alpha@...r.kernel.org, linux-snps-arc@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org, linux-csky@...r.kernel.org,
        linux-hexagon@...r.kernel.org, linux-ia64@...r.kernel.org,
        linux-m68k@...ts.linux-m68k.org, linux-mips@...r.kernel.org,
        openrisc@...ts.librecores.org, linux-parisc@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, linux-riscv@...ts.infradead.org,
        linux-s390@...r.kernel.org, linux-sh@...r.kernel.org,
        sparclinux@...r.kernel.org, linux-um@...ts.infradead.org,
        linux-xtensa@...ux-xtensa.org
Subject: Re: [PATCH 14/14] uaccess: drop set_fs leftovers

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?

Thanks,
Helge