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: Fri, 18 Sep 2020 14:36:23 +0200 From: Arnd Bergmann <arnd@...db.de> To: Russell King - ARM Linux admin <linux@...linux.org.uk> Cc: Christoph Hellwig <hch@....de>, Alexander Viro <viro@...iv.linux.org.uk>, linux- <kernel@...r.kernel.org>, linux-arch <linux-arch@...r.kernel.org>, Linux ARM <linux-arm-kernel@...ts.infradead.org>, Linus Walleij <linus.walleij@...aro.org>, Andrew Morton <akpm@...ux-foundation.org>, Dmitry Safonov <0x7f454c46@...il.com>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH 2/9] ARM: traps: use get_kernel_nofault instead of set_fs() On Fri, Sep 18, 2020 at 9:42 AM Russell King - ARM Linux admin <linux@...linux.org.uk> wrote: > > On Thu, Sep 17, 2020 at 07:29:37PM +0200, Arnd Bergmann wrote: > > On Tue, Sep 8, 2020 at 8:15 AM Christoph Hellwig <hch@....de> wrote: > > > > I looked through the history now and the only code path I could > > find that would arrive here this way is from bad_mode(), indicating > > that there is probably a hardware bug or the contents of *regs are > > corrupted. > > Yes, that's correct. It isn't something entirely theoretical, although > we never see it now, it used to happen in the distant past due to saved > regs corruption. If bad_mode() ever gets called, all bets are off and > we're irrecoverably crashing. > > Note that in that case, while user_mode(regs) may return true or false, > regs->ARM_sp and regs->ARM_lr are always the SVC mode stack and return > address after regs has been stacked, and not the expected values for > the parent context (which we have most likely long since destroyed.) Ok, I have rewritten the patch and my changelog text accordingly, sending an updated version now. Thanks, Arnd
Powered by blists - more mailing lists