From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
alan@linux.intel.com, kernel-hardening@lists.openwall.com,
tglx@linutronix.de, Mauro Carvalho Chehab <mchehab@kernel.org>,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
Elena Reshetova <elena.reshetova@intel.com>,
linux-media@vger.kernel.org
Subject: Re: [PATCH v2 14/19] [media] uvcvideo: prevent bounds-check bypass via speculative execution
Date: Tue, 07 Aug 2018 00:40:52 +0300 [thread overview]
Message-ID: <1624792.F9dcxCXkCx@avalon> (raw)
In-Reply-To: <151571806069.27429.6683179525235570687.stgit@dwillia2-desk3.amr.corp.intel.com>
Hi Dan,
Thank you for the patch.
On Friday, 12 January 2018 02:47:40 EEST Dan Williams wrote:
> Static analysis reports that 'index' may be a user controlled value that
> is used as a data dependency to read 'pin' from the
> 'selector->baSourceID' array. In order to avoid potential leaks of
> kernel memory values, block speculative execution of the instruction
> stream that could issue reads based on an invalid value of 'pin'.
>
> Based on an original patch by Elena Reshetova.
>
> Laurent notes:
>
> "...as this is nowhere close to being a fast path, I think we can close
> this potential hole as proposed in the patch"
>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: linux-media@vger.kernel.org
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
What's the status of this series (and of this patch in particular) ?
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c
> b/drivers/media/usb/uvc/uvc_v4l2.c index 3e7e283a44a8..30ee200206ee 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -22,6 +22,7 @@
> #include <linux/mm.h>
> #include <linux/wait.h>
> #include <linux/atomic.h>
> +#include <linux/nospec.h>
>
> #include <media/v4l2-common.h>
> #include <media/v4l2-ctrls.h>
> @@ -809,8 +810,12 @@ static int uvc_ioctl_enum_input(struct file *file, void
> *fh, const struct uvc_entity *selector = chain->selector;
> struct uvc_entity *iterm = NULL;
> u32 index = input->index;
> + __u8 *elem = NULL;
> int pin = 0;
>
> + if (selector)
> + elem = array_ptr(selector->baSourceID, index,
> + selector->bNrInPins);
> if (selector == NULL ||
> (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
> if (index != 0)
> @@ -820,8 +825,8 @@ static int uvc_ioctl_enum_input(struct file *file, void
> *fh, break;
> }
> pin = iterm->id;
> - } else if (index < selector->bNrInPins) {
> - pin = selector->baSourceID[index];
> + } else if (elem) {
> + pin = *elem;
> list_for_each_entry(iterm, &chain->entities, chain) {
> if (!UVC_ENTITY_IS_ITERM(iterm))
> continue;
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2018-08-06 21:40 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-12 0:46 [PATCH v2 00/19] prevent bounds-check bypass via speculative execution Dan Williams
2018-01-12 0:46 ` [PATCH v2 01/19] Documentation: document array_ptr Dan Williams
2018-01-12 10:38 ` Geert Uytterhoeven
2018-01-16 21:01 ` Kees Cook
2018-01-12 0:46 ` [PATCH v2 02/19] arm64: implement ifence_array_ptr() Dan Williams
2018-01-12 0:46 ` [PATCH v2 03/19] arm: " Dan Williams
2018-01-12 0:46 ` [PATCH v2 04/19] x86: implement ifence() Dan Williams
2018-01-12 2:27 ` Eric W. Biederman
2018-01-12 3:39 ` Dan Williams
2018-01-12 0:46 ` [PATCH v2 05/19] x86: implement ifence_array_ptr() and array_ptr_mask() Dan Williams
2018-01-12 0:46 ` [PATCH v2 06/19] asm-generic/barrier: mask speculative execution flows Dan Williams
2018-01-12 2:42 ` Eric W. Biederman
2018-01-12 9:12 ` Peter Zijlstra
2018-01-13 0:41 ` Dan Williams
2018-01-15 8:46 ` Peter Zijlstra
2018-01-12 0:47 ` [PATCH v2 07/19] x86: introduce __uaccess_begin_nospec and ASM_IFENCE Dan Williams
2018-01-12 17:51 ` Josh Poimboeuf
2018-01-12 18:21 ` Dan Williams
2018-01-12 18:58 ` Josh Poimboeuf
2018-01-12 19:26 ` Dan Williams
2018-01-12 20:01 ` Linus Torvalds
2018-01-12 20:41 ` Josh Poimboeuf
2018-01-12 0:47 ` [PATCH v2 08/19] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths Dan Williams
2018-01-12 1:11 ` Linus Torvalds
2018-01-12 1:14 ` Dan Williams
2018-01-12 0:47 ` [PATCH v2 09/19] ipv6: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-12 0:47 ` [PATCH v2 10/19] ipv4: " Dan Williams
2018-01-12 7:59 ` Greg KH
2018-01-12 18:47 ` Dan Williams
2018-01-13 8:56 ` Greg KH
2018-01-12 0:47 ` [PATCH v2 11/19] vfs, fdtable: " Dan Williams
2018-01-12 0:47 ` [PATCH v2 12/19] userns: " Dan Williams
2018-01-12 0:47 ` [PATCH v2 13/19] udf: " Dan Williams
2018-01-15 10:32 ` Jan Kara
2018-01-15 17:49 ` Dan Williams
2018-01-12 0:47 ` [PATCH v2 14/19] [media] uvcvideo: " Dan Williams
2018-08-06 21:40 ` Laurent Pinchart [this message]
2018-01-12 0:47 ` [PATCH v2 15/19] carl9170: " Dan Williams
2018-01-12 14:42 ` Christian Lamparter
2018-01-12 18:39 ` Dan Williams
2018-01-12 20:01 ` Christian Lamparter
2018-01-12 23:05 ` Dan Williams
2018-01-12 0:47 ` [PATCH v2 16/19] p54: " Dan Williams
2018-01-12 0:47 ` [PATCH v2 17/19] qla2xxx: " Dan Williams
2018-01-12 1:19 ` James Bottomley
2018-01-12 5:38 ` Dan Williams
2018-01-12 6:05 ` James Bottomley
2018-01-12 0:48 ` [PATCH v2 18/19] cw1200: " Dan Williams
2018-01-12 0:48 ` [PATCH v2 19/19] net: mpls: " Dan Williams
2018-01-12 1:19 ` [PATCH v2 00/19] " Linus Torvalds
2018-01-12 1:41 ` Dan Williams
2018-01-18 13:18 ` Will Deacon
2018-01-18 16:58 ` Dan Williams
2018-01-18 17:05 ` Will Deacon
2018-01-18 21:41 ` Laurent Pinchart
2018-01-13 0:15 ` Tony Luck
2018-01-13 18:51 ` Linus Torvalds
2018-01-16 19:21 ` Tony Luck
2018-01-12 10:02 ` Russell King - ARM Linux
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