public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Michael Ellerman <mpe@ellerman•id.au>
To: Kees Cook <keescook@chromium•org>
Cc: Breno Leitao <leitao@debian•org>,
	"linuxppc-dev\@lists.ozlabs.org" <linuxppc-dev@lists•ozlabs.org>,
	Laura Abbott <labbott@redhat•com>,
	gromero@br•ibm.com,
	Anshuman Khandual <khandual@linux•vnet.ibm.com>,
	Balbir Singh <bsingharora@gmail•com>
Subject: Re: kernel BUG at mm/usercopy.c:72!
Date: Thu, 18 May 2017 20:16:17 +1000	[thread overview]
Message-ID: <8737c2lbbi.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <CAGXu5jK86RkgsWFdtSuGoZzuRZt4cqJcU4YSTjn=irv0Pbu3Rw@mail.gmail.com>

Kees Cook <keescook@chromium•org> writes:
> On Tue, May 16, 2017 at 4:09 AM, Michael Ellerman <mpe@ellerman•id.au> wrote:
>> Yeah it looks like powerpc also suffers from the same bug that arm64
>> used to, ie. virt_addr_valid() will return true for some vmalloc
>> addresses.
>>
>> virt_addr_valid() is used pretty widely, I'm not sure if we can just fix
>> it without other fallout. I'll dig a bit more tomorrow if no one beats
>> me to it.
>>
>> Kees, depending on how that turns out we may ask you to revert
>> 517e1fbeb65f ("mm/usercopy: Drop extra is_vmalloc_or_module() check").
>
> That's fine by me. Let me know what you think would be best.

Oh man, what a mess.

I think we can do a small fix for this in powerpc code for 4.12, will
post it soon for Breno to test - I still can't reproduce locally.

cheers

  parent reply	other threads:[~2017-05-18 10:16 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-15 19:19 kernel BUG at mm/usercopy.c:72! Breno Leitao
2017-05-16  4:00 ` Anshuman Khandual
2017-05-16  4:44   ` Balbir Singh
2017-05-16  5:04     ` Anshuman Khandual
2017-05-16 11:02 ` Michael Ellerman
2017-05-16 16:15   ` Breno Leitao
2017-05-16 11:09 ` Michael Ellerman
2017-05-16 14:32   ` Kees Cook
2017-05-16 14:35     ` Laura Abbott
2017-05-18  5:09       ` Michael Ellerman
2017-05-17 10:05     ` Balbir Singh
2017-05-18 10:16     ` Michael Ellerman [this message]
2017-05-18 10:58       ` Balbir Singh
2017-05-18 10:17 ` Michael Ellerman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=8737c2lbbi.fsf@concordia.ellerman.id.au \
    --to=mpe@ellerman$(echo .)id.au \
    --cc=bsingharora@gmail$(echo .)com \
    --cc=gromero@br$(echo .)ibm.com \
    --cc=keescook@chromium$(echo .)org \
    --cc=khandual@linux$(echo .)vnet.ibm.com \
    --cc=labbott@redhat$(echo .)com \
    --cc=leitao@debian$(echo .)org \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox