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From: Vivek Goyal <vgoyal@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Roberto Sassu <roberto.sassu@polito.it>,
	Dmitry Kasatkin <dmitry.kasatkin@intel.com>,
	Kees Cook <keescook@chromium.org>,
	Peter Jones <pjones@redhat.com>,
	Mimi Zohar <zohar@linux.vnet.ibm.com>,
	kexec@lists.infradead.org,
	linux kernel mailing list <linux-kernel@vger.kernel.org>,
	horms@verge.net.au, "H. Peter Anvin" <hpa@zytor.com>,
	Matthew Garrett <mjg@redhat.com>, Dave Young <dyoung@redhat.com>,
	Khalid Aziz <khalid@gonehiking.org>
Subject: Re: Kdump with signed images
Date: Thu, 8 Nov 2012 14:40:51 -0500	[thread overview]
Message-ID: <20121108194050.GB27586@redhat.com> (raw)
In-Reply-To: <87k3tynvc0.fsf@xmission.com>

On Tue, Nov 06, 2012 at 03:51:59PM -0800, Eric W. Biederman wrote:

[..]

Thnking more about executable signature verification, I have another question.

While verifyign the signature, we will have to read the whole executable
in memory. That sounds bad as we are in kernel mode and will not be killed
and if sombody is trying to execute a malformed exceptionally large
executable, system will start killing other processess. We can potentially
lock all the memory in kernel just by trying to execute a signed huge
executable. Not good.

I was looking at IMA and they seem to be using kernel_read() for reading
page in and update digest. IIUC, that means page is read from disk,
brought in cache and if needed will be read back from disk. But that
means hacker can try to do some timing tricks and try to replace disk image
after signature verification and run unsigned program.

So how do we go about it. Neither of the approaches sound appealing
to me.

Thanks
Vivek

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  reply	other threads:[~2012-11-08 19:41 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-18  3:10 [PATCH v2] kdump: pass acpi_rsdp= to 2nd kernel for efi booting Dave Young
2012-10-18 14:56 ` Khalid Aziz
2012-10-18 19:11   ` Vivek Goyal
2012-10-18 19:22     ` Khalid Aziz
2012-10-18 19:38       ` [RFC] Kdump with UEFI secure boot (Re: [PATCH v2] kdump: pass acpi_rsdp= to 2nd kernel for efi booting) Vivek Goyal
2012-10-18 19:55         ` Matthew Garrett
2012-10-18 22:25         ` Eric W. Biederman
2012-10-19  2:06           ` Vivek Goyal
2012-10-19  3:36             ` Eric W. Biederman
2012-10-19 14:31               ` Vivek Goyal
2012-10-22 20:43                 ` Vivek Goyal
2012-10-22 21:11                   ` Eric W. Biederman
2012-10-23  2:04                   ` Simon Horman
2012-10-23 13:24                     ` Vivek Goyal
2012-10-23 16:26                       ` [RFC] Kdump with signed images Eric W. Biederman
2012-10-23 17:39                         ` Vivek Goyal
2012-10-23 19:11                           ` Maxim Uvarov
2012-10-23 19:16                             ` Vivek Goyal
2012-10-22 21:07                 ` [RFC] Kdump with UEFI secure boot (Re: [PATCH v2] kdump: pass acpi_rsdp= to 2nd kernel for efi booting) Eric W. Biederman
2012-10-23 13:18                   ` Vivek Goyal
2012-10-23 14:59                     ` Vivek Goyal
2012-10-23 15:41                       ` Matthew Garrett
2012-10-23 16:44                         ` [RFC] Kdump with signed images Eric W. Biederman
2012-10-23 16:52                           ` Matthew Garrett
2012-10-24 17:19                           ` Vivek Goyal
2012-10-25  5:43                             ` Mimi Zohar
2012-10-25  6:44                               ` Kees Cook
2012-10-25  7:01                                 ` Mimi Zohar
2012-10-25 13:54                               ` Vivek Goyal
2012-10-25 19:06                                 ` Mimi Zohar
2012-10-25 15:39                         ` [RFC] Kdump with UEFI secure boot (Re: [PATCH v2] kdump: pass acpi_rsdp= to 2nd kernel for efi booting) Vivek Goyal
2012-10-23 16:19                       ` Kdump with signed images Eric W. Biederman
2012-10-23 16:31                         ` Matthew Garrett
2012-10-23 17:03                           ` Eric W. Biederman
2012-10-23 17:09                             ` Matthew Garrett
2012-10-24 17:36                         ` Vivek Goyal
2012-10-25  6:10                           ` Mimi Zohar
2012-10-25 14:10                             ` Vivek Goyal
2012-10-25 18:40                               ` Mimi Zohar
2012-10-25 18:55                                 ` Vivek Goyal
2012-10-26  1:15                                   ` Mimi Zohar
2012-10-26  2:39                                     ` Matthew Garrett
2012-10-26  3:30                                       ` Eric W. Biederman
2012-10-26 17:06                                       ` Vivek Goyal
2012-10-26 18:37                                         ` Mimi Zohar
2012-11-01 13:10                                           ` Vivek Goyal
2012-11-01 13:53                                             ` Vivek Goyal
2012-11-01 14:29                                               ` Mimi Zohar
2012-11-01 14:43                                                 ` Vivek Goyal
2012-11-01 14:52                                                   ` Matthew Garrett
2012-11-02 13:23                                                     ` Vivek Goyal
2012-11-02 14:29                                                       ` Balbir Singh
2012-11-02 14:36                                                         ` Vivek Goyal
2012-11-03  3:02                                                           ` Balbir Singh
2012-11-02 21:34                                                         ` H. Peter Anvin
2012-11-02 21:32                                                       ` Eric W. Biederman
2012-11-05 18:03                                                         ` Vivek Goyal
2012-11-05 19:44                                                           ` Eric W. Biederman
2012-11-05 20:42                                                             ` Vivek Goyal
2012-11-05 23:01                                                               ` H. Peter Anvin
2012-11-06 19:34                                                             ` Vivek Goyal
2012-11-06 23:51                                                               ` Eric W. Biederman
2012-11-08 19:40                                                                 ` Vivek Goyal [this message]
2012-11-08 19:45                                                                   ` Vivek Goyal
2012-11-08 21:03                                                                     ` Eric W. Biederman
2012-11-09 14:39                                                                       ` Vivek Goyal
2012-11-15  5:09                                                                         ` Eric W. Biederman
2012-11-15 12:56                                                                           ` Mimi Zohar
2012-11-08 20:46                                                                   ` Mimi Zohar
2012-11-01 14:51                                                 ` Vivek Goyal
2012-11-01 14:57                                                   ` Matthew Garrett
2012-11-01 15:10                                                     ` Khalid Aziz
2012-11-01 16:23                                                       ` Matthew Garrett
2012-11-02 16:57                                                         ` Khalid Aziz
2012-10-26 17:59                                       ` Mimi Zohar
2012-10-26 18:19                                         ` Matthew Garrett
2012-10-26 18:25                                           ` Mimi Zohar
2012-10-23 15:51                     ` [RFC] Kdump with UEFI secure boot (Re: [PATCH v2] kdump: pass acpi_rsdp= to 2nd kernel for efi booting) Eric W. Biederman
2012-10-23 17:18                       ` Vivek Goyal
2012-10-19 17:53               ` Vivek Goyal
2012-10-22 21:15                 ` Eric W. Biederman
2012-11-02 21:36                   ` H. Peter Anvin
2012-11-05 18:11                     ` Vivek Goyal
2012-11-05 19:54                       ` Eric W. Biederman

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