From: Dan Williams <dan.j.williams@intel.com>
To: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arch@vger.kernel.org, Greg KH <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Netdev <netdev@vger.kernel.org>,
Eduardo Valentin <edubezval@gmail.com>,
Zhang Rui <rui.zhang@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Elena Reshetova <elena.reshetova@intel.com>,
Alan Cox <alan@linux.intel.com>
Subject: Re: [PATCH 12/18] Thermal/int340x: prevent bounds-check bypass via speculative execution
Date: Fri, 5 Jan 2018 17:57:18 -0800 [thread overview]
Message-ID: <CAPcyv4iNJrcKBiN+3=ZZ1MHU1PYbt4rLDLgWZY5Kc+O8regDYw@mail.gmail.com> (raw)
In-Reply-To: <1515203635.26317.78.camel@linux.intel.com>
On Fri, Jan 5, 2018 at 5:53 PM, Srinivas Pandruvada
<srinivas.pandruvada@linux.intel.com> wrote:
> On Fri, 2018-01-05 at 17:10 -0800, Dan Williams wrote:
>> Static analysis reports that 'trip' may be a user controlled value
>> that
>> is used as a data dependency to read '*temp' from the 'd->aux_trips'
>> 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 '*temp'.
>
> Not against the change as this is in a very slow path. But the trip is
> not an arbitrary value which user can enter.
>
> This trip value is the one of the sysfs attribute in thermal zone. For
> example
>
> # cd /sys/class/thermal/thermal_zone1
> # ls trip_point_?_temp
> trip_point_0_temp trip_point_1_temp trip_point_2_temp trip_point_3_t
> emp trip_point_4_temp trip_point_5_temp trip_point_6_temp
>
> Here the "trip" is one of the above trip_point_*_temp. So in this case
> it can be from 0 to 6 as user can't do
> # cat trip_point_7_temp
> as there is no sysfs attribute for trip_point_7_temp.
>
> The actual "trip" was obtained in thermal core via
>
> if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
> return -EINVAL;
>
> Thanks,
> Srinivas
Ah, great, thanks. So do we even need the bounds check at that point?
next prev parent reply other threads:[~2018-01-06 1:57 UTC|newest]
Thread overview: 161+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-06 1:09 [PATCH 00/18] prevent bounds-check bypass via speculative execution Dan Williams
2018-01-06 1:09 ` [PATCH 01/18] asm-generic/barrier: add generic nospec helpers Dan Williams
2018-01-06 2:55 ` Linus Torvalds
2018-01-06 5:23 ` Dan Williams
2018-01-06 17:08 ` Mark Rutland
2018-01-06 1:10 ` [PATCH 02/18] Documentation: document " Dan Williams
2018-01-08 16:29 ` Jonathan Corbet
2018-01-08 17:09 ` Mark Rutland
2018-01-08 21:19 ` Jonathan Corbet
2018-01-06 1:10 ` [PATCH 03/18] arm64: implement nospec_ptr() Dan Williams
2018-01-06 1:10 ` [PATCH 04/18] arm: " Dan Williams
2018-01-10 2:04 ` Laura Abbott
2018-01-10 7:40 ` Hanjun Guo
2018-01-10 17:24 ` Laura Abbott
2018-01-06 1:10 ` [PATCH 05/18] x86: implement nospec_barrier() Dan Williams
2018-01-06 1:10 ` [PATCH 06/18] x86, barrier: stop speculation for failed access_ok Dan Williams
2018-01-06 2:52 ` Linus Torvalds
2018-01-06 3:09 ` Linus Torvalds
2018-01-06 23:31 ` Dan Williams
2018-01-07 1:20 ` Linus Torvalds
2018-01-08 21:09 ` Dan Williams
2018-01-08 23:44 ` Linus Torvalds
2018-01-08 23:53 ` Dan Williams
2018-01-06 5:47 ` Dan Williams
2018-01-06 12:32 ` Alan Cox
2018-01-06 17:56 ` Linus Torvalds
2018-01-06 18:13 ` Alexei Starovoitov
2018-01-06 18:29 ` Dan Williams
2018-01-06 18:39 ` Alexei Starovoitov
2018-01-06 18:54 ` Dan Williams
2018-01-06 19:25 ` Alexei Starovoitov
2018-01-06 19:36 ` Dan Williams
2018-01-06 19:41 ` Thomas Gleixner
2018-01-08 10:02 ` Andrea Arcangeli
2018-01-06 18:38 ` Alan Cox
2018-01-06 18:51 ` Alexei Starovoitov
2018-01-06 19:55 ` Alan Cox
2018-01-06 20:09 ` Alexei Starovoitov
2018-01-06 20:22 ` Alan Cox
2018-01-06 21:17 ` Alexei Starovoitov
2018-01-06 21:21 ` Thomas Gleixner
2018-01-06 23:05 ` Alan Cox
2018-01-07 3:38 ` Alexei Starovoitov
2018-01-07 6:33 ` Willy Tarreau
2018-01-07 19:47 ` Linus Torvalds
2018-01-07 20:12 ` Willy Tarreau
2018-01-07 20:17 ` Linus Torvalds
2018-01-07 20:56 ` Thomas Gleixner
2018-01-08 2:23 ` David Miller
2018-01-08 7:38 ` Greg KH
2018-01-07 22:15 ` Willy Tarreau
2018-01-07 20:15 ` Dan Williams
2018-01-08 2:24 ` Alexei Starovoitov
2018-01-08 9:51 ` Peter Zijlstra
2018-01-08 18:21 ` Ingo Molnar
2018-01-08 12:00 ` David Laight
2018-01-08 12:12 ` Alan Cox
2018-01-08 12:33 ` David Laight
2018-01-07 10:08 ` Thomas Gleixner
2018-01-08 2:09 ` Alexei Starovoitov
2018-01-07 13:59 ` Alan Cox
2018-01-08 2:57 ` Alexei Starovoitov
2018-01-08 9:57 ` Peter Zijlstra
2018-01-06 20:42 ` Willy Tarreau
2018-01-07 1:36 ` David Miller
2018-01-07 17:19 ` James Bottomley
2018-01-07 18:31 ` Thomas Gleixner
2018-01-08 2:04 ` David Miller
2018-01-07 19:24 ` Alan Cox
2018-01-09 21:41 ` Josh Poimboeuf
2018-01-09 21:47 ` Dan Williams
2018-01-09 21:49 ` Josh Poimboeuf
2018-01-09 21:59 ` Dan Williams
2018-01-09 22:23 ` Josh Poimboeuf
2018-01-09 22:35 ` Dan Williams
2018-01-06 1:10 ` [PATCH 07/18] [media] uvcvideo: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-06 9:09 ` Greg KH
2018-01-06 9:40 ` Greg KH
2018-01-06 17:41 ` Dan Williams
2018-01-07 9:09 ` Greg KH
2018-01-07 19:37 ` Dan Williams
2018-01-09 8:40 ` Laurent Pinchart
2018-01-09 10:04 ` Greg KH
2018-01-09 14:26 ` Laurent Pinchart
2018-01-09 14:47 ` Greg KH
2018-01-08 11:23 ` Laurent Pinchart
2018-01-09 2:11 ` Dan Williams
2018-01-06 1:10 ` [PATCH 08/18] carl9170: " Dan Williams
2018-01-06 10:01 ` Sergei Shtylyov
2018-01-06 14:23 ` Christian Lamparter
2018-01-06 15:06 ` Alan Cox
2018-01-06 16:38 ` Christian Lamparter
2018-01-06 16:34 ` Dan Williams
2018-01-06 1:10 ` [PATCH 09/18] p54: " Dan Williams
2018-01-06 10:01 ` Sergei Shtylyov
2018-01-06 1:10 ` [PATCH 10/18] qla2xxx: " Dan Williams
2018-01-06 9:03 ` Greg KH
2018-01-06 9:42 ` Greg KH
2018-01-11 22:15 ` Dan Williams
2018-01-12 7:27 ` Greg KH
2018-01-12 15:25 ` James Bottomley
2018-01-06 1:10 ` [PATCH 11/18] cw1200: " Dan Williams
2018-01-06 1:10 ` [PATCH 12/18] Thermal/int340x: " Dan Williams
2018-01-06 1:53 ` Srinivas Pandruvada
2018-01-06 1:57 ` Dan Williams [this message]
2018-01-06 17:24 ` Srinivas Pandruvada
2018-01-06 10:03 ` Sergei Shtylyov
2018-01-06 1:11 ` [PATCH 13/18] ipv6: " Dan Williams
2018-01-06 10:04 ` Sergei Shtylyov
2018-01-06 14:48 ` Stephen Hemminger
2018-01-06 18:05 ` Dan Williams
2018-01-06 1:11 ` [PATCH 14/18] ipv4: " Dan Williams
2018-01-06 9:00 ` Greg KH
2018-01-06 9:01 ` Greg KH
2018-01-06 12:23 ` Alan Cox
2018-01-06 15:14 ` Greg KH
2018-01-06 16:29 ` Dan Williams
2018-01-06 18:10 ` Dan Williams
2018-01-06 10:04 ` Sergei Shtylyov
2018-01-06 1:11 ` [PATCH 15/18] vfs, fdtable: " Dan Williams
2018-01-06 10:05 ` Sergei Shtylyov
2018-01-06 1:11 ` [PATCH 16/18] net: mpls: " Dan Williams
2018-01-06 10:06 ` Sergei Shtylyov
2018-01-09 3:11 ` Eric W. Biederman
2018-01-09 3:42 ` Dan Williams
2018-01-09 4:13 ` Linus Torvalds
2018-01-09 4:21 ` Linus Torvalds
2018-01-10 0:48 ` Dan Williams
2018-01-10 1:33 ` Dan Williams
2018-01-10 1:57 ` Alexei Starovoitov
2018-01-10 2:22 ` Dan Williams
2018-01-10 3:07 ` Alexei Starovoitov
2018-01-10 3:27 ` Linus Torvalds
2018-01-09 16:17 ` Eric W. Biederman
2018-01-09 18:01 ` Dan Williams
2018-01-10 0:54 ` Eric W. Biederman
2018-01-10 1:31 ` Dan Williams
2018-01-06 1:11 ` [PATCH 17/18] udf: " Dan Williams
2018-01-08 10:20 ` Jan Kara
2018-01-06 1:11 ` [PATCH 18/18] userns: " Dan Williams
2018-01-06 2:22 ` [PATCH 00/18] " Eric W. Biederman
2018-01-06 6:30 ` Dan Williams
2018-01-08 10:08 ` Peter Zijlstra
2018-01-08 11:14 ` Laurent Pinchart
2018-01-08 11:43 ` Alan Cox
2018-01-08 11:55 ` Peter Zijlstra
2018-01-08 18:33 ` Ingo Molnar
2018-01-08 16:20 ` Bart Van Assche
2018-01-06 18:56 ` Florian Fainelli
2018-01-06 18:59 ` Arjan van de Ven
2018-01-06 19:37 ` Dan Williams
2018-01-06 20:07 ` Dan Williams
2018-01-08 4:49 ` Bart Van Assche
2018-01-08 13:33 ` Arjan van de Ven
2018-01-09 19:34 ` Jiri Kosina
2018-01-09 19:44 ` Dan Williams
2018-01-09 20:55 ` Josh Poimboeuf
2018-01-11 9:54 ` Jiri Kosina
2018-01-11 15:58 ` Dan Williams
2018-01-11 16:34 ` Daniel Borkmann
2018-01-13 11:33 ` QingFeng Hao
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