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
| ||
|
Date: Wed, 2 Sep 2020 15:24:39 +0200 From: Christophe Leroy <christophe.leroy@...roup.eu> To: David Laight <David.Laight@...LAB.COM>, 'Christoph Hellwig' <hch@....de> Cc: Linus Torvalds <torvalds@...ux-foundation.org>, Al Viro <viro@...iv.linux.org.uk>, Michael Ellerman <mpe@...erman.id.au>, "x86@...nel.org" <x86@...nel.org>, "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>, "linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>, "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>, Kees Cook <keescook@...omium.org>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH 10/10] powerpc: remove address space overrides using set_fs() Le 02/09/2020 à 15:13, David Laight a écrit : > From: Christoph Hellwig >> Sent: 02 September 2020 13:37 >> >> On Wed, Sep 02, 2020 at 08:15:12AM +0200, Christophe Leroy wrote: >>>> - return 0; >>>> - return (size == 0 || size - 1 <= seg.seg - addr); >>>> + if (addr >= TASK_SIZE_MAX) >>>> + return false; >>>> + if (size == 0) >>>> + return false; >>> >>> __access_ok() was returning true when size == 0 up to now. Any reason to >>> return false now ? >> >> No, this is accidental and broken. Can you re-run your benchmark with >> this fixed? > > Is TASK_SIZE_MASK defined such that you can do: > > return (addr | size) < TASK_SIZE_MAX) || !size; TASK_SIZE_MAX will usually be 0xc0000000 With: addr = 0x80000000; size = 0x80000000; I expect it to fail .... With the formula you propose it will succeed, won't it ? Christophe
Powered by blists - more mailing lists