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From: Laura Abbott <labbott@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@fedoraproject.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Arnd Bergmann <arnd@arndb.de>,
	"kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCHv2] lkdtm: Add READ_AFTER_FREE test
Date: Wed, 24 Feb 2016 10:59:22 -0800	[thread overview]
Message-ID: <56CDFD8A.1040000@redhat.com> (raw)
In-Reply-To: <CAGXu5jL8xBHUkZP8_MZk84Zr5efEUGL8z-o0u5_4ybX4CrAmPQ@mail.gmail.com>

On 02/23/2016 02:37 PM, Kees Cook wrote:
> On Tue, Feb 23, 2016 at 1:25 PM, Kees Cook <keescook@chromium.org> wrote:
>
>> zero poison only:
>> DEBUG_PAGEALLOC=n
>> PAGE_POISONING=y
>> PAGE_POISONING_NO_SANITY=y
>> PAGE_POISONING_ZERO=y
>> page_poison=on
>
> This combo (in next-20160223) results in an unusable system. :(
>
> [    1.754183] random: init urandom read with 11 bits of entropy available
> [    1.768449] hostname (1171) used greatest stack depth: 11808 bytes left
> [    1.787954] BUG: Bad page map in process init  pte:3d656c6f736e6f63
> pmd:00020067
> [    1.789177] addr:00007f9f68200000 vm_flags:00000070 anon_vma:
>     (null) mapping:ffff88007c314058 index:141
> [    1.790564] file:libdl-2.19.so fault:ext4_filemap_fault
> mmap:ext4_file_mmap readpage:ext4_readpage
>
> -Kees
>

Hmmm, it looks like the -mm tree currently only has the v1 of the
poisoning patches and not the v2. The v1 had a bug which would
cause issues like this due to some pages not getting zeroed fully. I should
follow up on that today.

Thanks,
Laura

  reply	other threads:[~2016-02-24 18:59 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-19  1:15 [PATCHv2] lkdtm: Add READ_AFTER_FREE test Laura Abbott
2016-02-19 19:12 ` Kees Cook
2016-02-19 22:11   ` Laura Abbott
2016-02-19 22:19     ` Kees Cook
2016-02-19 23:07       ` Laura Abbott
2016-02-22 19:27         ` Kees Cook
2016-02-22 22:06           ` Laura Abbott
2016-02-23 21:25             ` Kees Cook
2016-02-23 22:37               ` Kees Cook
2016-02-24 18:59                 ` Laura Abbott [this message]
2016-02-24 17:22               ` Kees Cook
2016-02-24 19:40                 ` Laura Abbott
2016-02-24 21:48                   ` Kees Cook
2016-02-24 23:37                     ` Kees Cook
2016-02-25  1:28                       ` Laura Abbott
2016-02-25 17:35                         ` Kees Cook
2016-02-25 23:15                           ` Laura Abbott
2016-02-26 16:03                             ` Kees Cook
2016-02-26 22:19                               ` Laura Abbott
2016-02-26 22:33                                 ` Kees Cook
2016-03-01  1:37                                   ` Laura Abbott

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