* Re: [PATCH] drm/i915: Fix potential spectre vulnerability
2023-11-02 11:32 ` Tvrtko Ursulin
@ 2023-11-03 0:07 ` Andi Shyti
2023-11-03 2:31 ` Kunwu Chan
2023-11-03 2:32 ` [PATCH v2] " Kunwu Chan
2 siblings, 0 replies; 9+ messages in thread
From: Andi Shyti @ 2023-11-03 0:07 UTC (permalink / raw)
To: Tvrtko Ursulin
Cc: chentao, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, andi.shyti, robdclark, jonathan.cavitt, andrzej.hajda,
chris.p.wilson, alan.previn.teres.alexis, intel-gfx, dri-devel,
linux-kernel, kunwu.chan
Hi,
On Thu, Nov 02, 2023 at 11:32:43AM +0000, Tvrtko Ursulin wrote:
> On 02/11/2023 10:16, chentao wrote:
> > Fix smatch warning:
> > drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
> > warn: potential spectre issue 'pc->user_engines' [r] (local cap)
> >
> > Signed-off-by: chentao <chentao@kylinos.cn>
>
> I don't know if this is actually exploitable given the time deltas between the index is read from userspace and acted upon here, which is at least two ioctls apart. But I suppose no harm in fixing and for safety so we need to add:
>
> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
> Cc: <stable@vger.kernel.org> # v5.15+
Is this a real fix? I don't mind adding it, though.
> > ---
> > drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index 9a9ff84c90d7..b2fdfc7ca4de 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -843,7 +843,7 @@ static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
> > if (idx >= pc->num_user_engines)
> > return -EINVAL;
> > -
>
> Just please refrain from random whitespace modifications like this blank line removal. If you resend without that you can add my r-b.
>
> Regards,
>
> Tvrtko
>
> > + idx = array_index_nospec(idx, pc->num_user_engines);
idx has been assigned earlier, can we make it one single
assignment at the declaration?
Andi
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] drm/i915: Fix potential spectre vulnerability
2023-11-02 11:32 ` Tvrtko Ursulin
2023-11-03 0:07 ` Andi Shyti
@ 2023-11-03 2:31 ` Kunwu Chan
2023-11-03 2:32 ` [PATCH v2] " Kunwu Chan
2 siblings, 0 replies; 9+ messages in thread
From: Kunwu Chan @ 2023-11-03 2:31 UTC (permalink / raw)
To: Tvrtko Ursulin, jani.nikula, joonas.lahtinen, rodrigo.vivi,
airlied, daniel, andi.shyti, robdclark, jonathan.cavitt,
andrzej.hajda, chris.p.wilson, alan.previn.teres.alexis
Cc: intel-gfx, dri-devel, linux-kernel, kunwu.chan
Hi Tvrtko,
Thank you very much for your kind suggestion, I have modified it in
accordance with your suggestion.
On 2023/11/2 19:32, Tvrtko Ursulin wrote:
>
> On 02/11/2023 10:16, chentao wrote:
>> Fix smatch warning:
>> drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
>> warn: potential spectre issue 'pc->user_engines' [r] (local cap)
>>
>> Signed-off-by: chentao <chentao@kylinos.cn>
>
> I don't know if this is actually exploitable given the time deltas
> between the index is read from userspace and acted upon here, which is
> at least two ioctls apart. But I suppose no harm in fixing and for
> safety so we need to add:
>
> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle
> create parameters (v5)")
> Cc: <stable@vger.kernel.org> # v5.15+
>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> index 9a9ff84c90d7..b2fdfc7ca4de 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> @@ -843,7 +843,7 @@ static int set_proto_ctx_sseu(struct
>> drm_i915_file_private *fpriv,
>> if (idx >= pc->num_user_engines)
>> return -EINVAL;
>> -
>
> Just please refrain from random whitespace modifications like this blank
> line removal. If you resend without that you can add my r-b.
>
> Regards,
>
> Tvrtko
>
>> + idx = array_index_nospec(idx, pc->num_user_engines);
>> pe = &pc->user_engines[idx];
>> /* Only render engine supports RPCS configuration. */
^ permalink raw reply [flat|nested] 9+ messages in thread* [PATCH v2] drm/i915: Fix potential spectre vulnerability
2023-11-02 11:32 ` Tvrtko Ursulin
2023-11-03 0:07 ` Andi Shyti
2023-11-03 2:31 ` Kunwu Chan
@ 2023-11-03 2:32 ` Kunwu Chan
2023-11-03 6:56 ` Krzysztof Kozlowski
2023-11-06 9:57 ` Andi Shyti
2 siblings, 2 replies; 9+ messages in thread
From: Kunwu Chan @ 2023-11-03 2:32 UTC (permalink / raw)
To: tvrtko.ursulin
Cc: airlied, alan.previn.teres.alexis, andi.shyti, andrzej.hajda,
chentao, chris.p.wilson, daniel, dri-devel, intel-gfx,
jani.nikula, jonathan.cavitt, joonas.lahtinen, kunwu.chan,
linux-kernel, robdclark, rodrigo.vivi, stable
Fix smatch warning:
drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
warn: potential spectre issue 'pc->user_engines' [r] (local cap)
Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
Cc: <stable@vger.kernel.org> # v5.15+
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: https://lore.kernel.org/all/20231102101642.52988-1-chentao@kylinos.cn
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 9a9ff84c90d7..e38f06a6e56e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -844,6 +844,7 @@ static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
if (idx >= pc->num_user_engines)
return -EINVAL;
+ idx = array_index_nospec(idx, pc->num_user_engines);
pe = &pc->user_engines[idx];
/* Only render engine supports RPCS configuration. */
--
2.34.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v2] drm/i915: Fix potential spectre vulnerability
2023-11-03 2:32 ` [PATCH v2] " Kunwu Chan
@ 2023-11-03 6:56 ` Krzysztof Kozlowski
2023-11-03 8:23 ` Tvrtko Ursulin
2023-11-06 9:57 ` Andi Shyti
1 sibling, 1 reply; 9+ messages in thread
From: Krzysztof Kozlowski @ 2023-11-03 6:56 UTC (permalink / raw)
To: Kunwu Chan, tvrtko.ursulin
Cc: airlied, alan.previn.teres.alexis, andi.shyti, andrzej.hajda,
chris.p.wilson, daniel, dri-devel, intel-gfx, jani.nikula,
jonathan.cavitt, joonas.lahtinen, kunwu.chan, linux-kernel,
robdclark, rodrigo.vivi, stable
On 03/11/2023 03:32, Kunwu Chan wrote:
> Fix smatch warning:
> drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
> warn: potential spectre issue 'pc->user_engines' [r] (local cap)
>
> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
> Cc: <stable@vger.kernel.org> # v5.15+
> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
> Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Where did you receive this tag? There is nothing under link below.
> Link: https://lore.kernel.org/all/20231102101642.52988-1-chentao@kylinos.cn
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH v2] drm/i915: Fix potential spectre vulnerability
2023-11-03 6:56 ` Krzysztof Kozlowski
@ 2023-11-03 8:23 ` Tvrtko Ursulin
0 siblings, 0 replies; 9+ messages in thread
From: Tvrtko Ursulin @ 2023-11-03 8:23 UTC (permalink / raw)
To: Krzysztof Kozlowski, Kunwu Chan
Cc: airlied, alan.previn.teres.alexis, andi.shyti, andrzej.hajda,
chris.p.wilson, daniel, dri-devel, intel-gfx, jani.nikula,
jonathan.cavitt, joonas.lahtinen, kunwu.chan, linux-kernel,
robdclark, rodrigo.vivi, stable
On 03/11/2023 06:56, Krzysztof Kozlowski wrote:
> On 03/11/2023 03:32, Kunwu Chan wrote:
>> Fix smatch warning:
>> drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
>> warn: potential spectre issue 'pc->user_engines' [r] (local cap)
>>
>> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
>> Cc: <stable@vger.kernel.org> # v5.15+
>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
>> Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
>> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
>
> Where did you receive this tag? There is nothing under link below.
>> Link: https://lore.kernel.org/all/20231102101642.52988-1-chentao@kylinos.cn
It is fine, I gave the conditional r-b in
https://lore.kernel.org/all/d300506c-ab82-4cc1-b750-61e54ec2ad9e@linux.intel.com/.
Suggested-by I did not and it is not true so I can drop it while applying.
Regards,
Tvrtko
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] drm/i915: Fix potential spectre vulnerability
2023-11-03 2:32 ` [PATCH v2] " Kunwu Chan
2023-11-03 6:56 ` Krzysztof Kozlowski
@ 2023-11-06 9:57 ` Andi Shyti
2023-11-06 10:15 ` Tvrtko Ursulin
1 sibling, 1 reply; 9+ messages in thread
From: Andi Shyti @ 2023-11-06 9:57 UTC (permalink / raw)
To: Kunwu Chan
Cc: tvrtko.ursulin, airlied, alan.previn.teres.alexis, andi.shyti,
andrzej.hajda, chris.p.wilson, daniel, dri-devel, intel-gfx,
jani.nikula, jonathan.cavitt, joonas.lahtinen, kunwu.chan,
linux-kernel, robdclark, rodrigo.vivi, stable
Hi Kunwu,
On Fri, Nov 03, 2023 at 10:32:57AM +0800, Kunwu Chan wrote:
> Fix smatch warning:
> drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
> warn: potential spectre issue 'pc->user_engines' [r] (local cap)
>
> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
> Cc: <stable@vger.kernel.org> # v5.15+
> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
> Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
> Link: https://lore.kernel.org/all/20231102101642.52988-1-chentao@kylinos.cn
> ---
> drivers/gpu/drm/i915/gem/i915_gem_context.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 9a9ff84c90d7..e38f06a6e56e 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -844,6 +844,7 @@ static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
> if (idx >= pc->num_user_engines)
> return -EINVAL;
>
> + idx = array_index_nospec(idx, pc->num_user_engines);
you ignored my comment, though.
Andi
> pe = &pc->user_engines[idx];
>
> /* Only render engine supports RPCS configuration. */
> --
> 2.34.1
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH v2] drm/i915: Fix potential spectre vulnerability
2023-11-06 9:57 ` Andi Shyti
@ 2023-11-06 10:15 ` Tvrtko Ursulin
0 siblings, 0 replies; 9+ messages in thread
From: Tvrtko Ursulin @ 2023-11-06 10:15 UTC (permalink / raw)
To: Andi Shyti, Kunwu Chan
Cc: airlied, alan.previn.teres.alexis, andrzej.hajda, chris.p.wilson,
daniel, dri-devel, intel-gfx, jani.nikula, jonathan.cavitt,
joonas.lahtinen, kunwu.chan, linux-kernel, robdclark,
rodrigo.vivi, stable
On 06/11/2023 09:57, Andi Shyti wrote:
> Hi Kunwu,
>
> On Fri, Nov 03, 2023 at 10:32:57AM +0800, Kunwu Chan wrote:
>> Fix smatch warning:
>> drivers/gpu/drm/i915/gem/i915_gem_context.c:847 set_proto_ctx_sseu()
>> warn: potential spectre issue 'pc->user_engines' [r] (local cap)
>>
>> Fixes: d4433c7600f7 ("drm/i915/gem: Use the proto-context to handle create parameters (v5)")
>> Cc: <stable@vger.kernel.org> # v5.15+
>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
>> Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
>> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
>> Link: https://lore.kernel.org/all/20231102101642.52988-1-chentao@kylinos.cn
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_context.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> index 9a9ff84c90d7..e38f06a6e56e 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
>> @@ -844,6 +844,7 @@ static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
>> if (idx >= pc->num_user_engines)
>> return -EINVAL;
>>
>> + idx = array_index_nospec(idx, pc->num_user_engines);
>
> you ignored my comment, though.
Sorry it was me, I considered it fine as is given it is the same pattern
as elsewhere in the file. I've merged the patch btw.
Regards,
Tvrtko
>
> Andi
>
>> pe = &pc->user_engines[idx];
>>
>> /* Only render engine supports RPCS configuration. */
>> --
>> 2.34.1
^ permalink raw reply [flat|nested] 9+ messages in thread