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From: Matthew Garrett <mjg59@google.com>
To: tony.luck@intel.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	joe.konno@linux.intel.com, linux-efi <linux-efi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	matthew.garrett@nebula.com, jk@ozlabs.org, ak@linux.intel.com,
	pjones@redhat.com, luto@kernel.org,
	James Bottomley <james.bottomley@hansenpartnership.com>
Subject: Re: [PATCH 1/2] fs/efivarfs: restrict inode permissions
Date: Tue, 20 Feb 2018 21:35:20 +0000	[thread overview]
Message-ID: <CACdnJuvR1h+qn=EqiWDAR3m1LcPyqMszLbQbO0j9b3HYkc1nDQ@mail.gmail.com> (raw)
In-Reply-To: <20180220213246.43y2vbiiikqyx2ys@agluck-desk>

On Tue, Feb 20, 2018 at 1:32 PM Luck, Tony <tony.luck@intel.com> wrote:

> The immediate problem is the denial of service attack.  I have
> a nagging worry that allowing a user to cause an SMI at a precise
> time might also be a problem. But I don't know how that could be
> leveraged in some other attack.

The thing that worries me here is that if it's possible for root to
potentially attack the kernel then just changing the permissions is still
allowing an escalation of privilege. The other approaches would also block
this.

  reply	other threads:[~2018-02-20 21:35 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-15 18:22 [PATCH 0/2] efivars: reading variables can generate SMIs Joe Konno
2018-02-15 18:22 ` [PATCH 1/2] fs/efivarfs: restrict inode permissions Joe Konno
2018-02-20 19:18   ` Andy Lutomirski
2018-02-20 21:18     ` Luck, Tony
2018-02-20 21:22       ` Matthew Garrett
2018-02-20 21:32         ` Luck, Tony
2018-02-20 21:35           ` Matthew Garrett [this message]
2018-02-20 22:01       ` Linus Torvalds
2018-02-20 23:30         ` Luck, Tony
2018-02-20 23:39           ` Matthew Garrett
2018-02-20 23:50             ` Luck, Tony
2018-02-21  0:49           ` Linus Torvalds
2018-02-21  1:05             ` Luck, Tony
2018-02-21  2:16               ` Linus Torvalds
2018-02-21  9:03                 ` Ard Biesheuvel
2018-02-21 18:02                   ` Linus Torvalds
2018-02-21 18:21                     ` Andi Kleen
2018-02-21 19:47                       ` Luck, Tony
2018-02-21 19:50                         ` Linus Torvalds
2018-02-21 19:58                           ` Luck, Tony
2018-02-21 20:40                             ` Linus Torvalds
2018-02-22  1:45                               ` [PATCH] efivarfs: Limit the rate for non-root to read files Luck, Tony
2018-02-22  1:58                                 ` Linus Torvalds
2018-02-22  5:34                                   ` Luck, Tony
2018-02-22 17:10                                     ` Eric W. Biederman
     [not found]                                     ` <CA+55aFy0hRexJkLbN7t31LjfGr4Ae0W5g6sBMqHHJi8aYuGKeA@mail.gmail.com>
     [not found]                                       ` <612E894E-62C8-4155-AED8-D53702EDC8DC@intel.com>
     [not found]                                         ` <CA+55aFxeBaTbwvbWqx1MKYjKKzLUs=1O43Bx2=JaO8qrnY-8HA@mail.gmail.com>
2018-02-22 17:15                                           ` [PATCH v2] " Luck, Tony
2018-02-22 17:39                                             ` Linus Torvalds
2018-02-22 17:54                                               ` Luck, Tony
2018-02-22 18:07                                                 ` Linus Torvalds
2018-02-22 18:08                                                   ` Ard Biesheuvel
2018-02-23 20:34                                                     ` Andy Lutomirski
2018-02-23 19:47                                         ` [PATCH] " Peter Jones
2018-02-21 19:52                       ` [PATCH 1/2] fs/efivarfs: restrict inode permissions Linus Torvalds
2018-02-24 20:06                   ` Alan Cox
2018-02-25 10:56                     ` Ard Biesheuvel
2018-02-21  0:49         ` Peter Jones
2018-02-20 23:19     ` Andy Lutomirski
2018-02-15 18:22 ` [PATCH 2/2] efi: restrict top-level attribute permissions Joe Konno
2018-02-15 18:22   ` Joe Konno
2018-02-16 10:41 ` [PATCH 0/2] efivars: reading variables can generate SMIs Ard Biesheuvel
2018-02-16 10:55   ` Borislav Petkov
2018-02-16 10:58     ` Ard Biesheuvel
2018-02-16 11:08       ` Borislav Petkov
2018-02-16 11:18         ` Ard Biesheuvel
2018-02-16 11:18           ` Ard Biesheuvel
2018-02-16 18:48           ` Joe Konno
2018-02-16 18:48             ` Joe Konno
2018-02-16 18:58             ` Borislav Petkov
2018-02-16 19:22             ` Peter Jones
2018-02-16 19:31               ` Ard Biesheuvel
2018-02-16 19:51                 ` Matthew Garrett
2018-02-16 19:51                   ` Matthew Garrett
2018-02-16 19:32               ` Luck, Tony
2018-02-16 19:54                 ` Peter Jones
2018-02-16 20:51   ` James Bottomley
2018-02-16 20:51     ` James Bottomley
2018-02-16 21:09     ` Luck, Tony
2018-02-16 21:09       ` Luck, Tony
2018-02-16 21:45       ` Andy Lutomirski
2018-02-16 21:58         ` Matthew Garrett
2018-02-16 22:02           ` Luck, Tony
2018-02-16 22:02             ` Luck, Tony
2018-02-16 22:03             ` Matthew Garrett
2018-02-16 22:03               ` Matthew Garrett
2018-02-17 18:12               ` Andy Lutomirski
2018-02-17 18:12                 ` Andy Lutomirski
2018-02-16 22:05       ` Peter Jones
2018-02-17  9:36         ` Ard Biesheuvel
2018-02-17  9:36           ` Ard Biesheuvel
2018-02-17 16:17           ` Andi Kleen
2018-02-17 16:17             ` Andi Kleen

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