* [PATCH] drm/rockchip: Don't allow zero sized gem buffer
@ 2017-05-23 6:39 Jeffy Chen
2017-05-25 15:30 ` Sean Paul
0 siblings, 1 reply; 6+ messages in thread
From: Jeffy Chen @ 2017-05-23 6:39 UTC (permalink / raw)
To: linux-kernel
Cc: seanpaul, tfiga, Jeffy Chen, Mark Yao, Heiko Stuebner, dri-devel,
linux-rockchip, David Airlie, linux-arm-kernel
The system would crash when trying to alloc zero sized gem buffer:
[ 6.712435] Unable to handle kernel NULL pointer dereference at virtual address 00000010 <--ZERO_SIZE_PTR
...
[ 6.757502] PC is at sg_alloc_table_from_pages+0x170/0x1ec
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---
drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index df9e570..8917922 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -315,6 +315,11 @@ struct rockchip_gem_object *
struct drm_gem_object *obj;
int ret;
+ if (!size) {
+ DRM_ERROR("gem buffer size is zero\n");
+ return ERR_PTR(-EINVAL);
+ }
+
size = round_up(size, PAGE_SIZE);
rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
--
2.1.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/rockchip: Don't allow zero sized gem buffer
2017-05-23 6:39 [PATCH] drm/rockchip: Don't allow zero sized gem buffer Jeffy Chen
@ 2017-05-25 15:30 ` Sean Paul
2017-05-26 2:30 ` jeffy
0 siblings, 1 reply; 6+ messages in thread
From: Sean Paul @ 2017-05-25 15:30 UTC (permalink / raw)
To: Jeffy Chen
Cc: linux-kernel, seanpaul, tfiga, Mark Yao, Heiko Stuebner,
dri-devel, linux-rockchip, David Airlie, linux-arm-kernel
On Tue, May 23, 2017 at 02:39:43PM +0800, Jeffy Chen wrote:
> The system would crash when trying to alloc zero sized gem buffer:
> [ 6.712435] Unable to handle kernel NULL pointer dereference at virtual address 00000010 <--ZERO_SIZE_PTR
> ...
> [ 6.757502] PC is at sg_alloc_table_from_pages+0x170/0x1ec
It's unfortunate that you didn't include the entire stack trace. From code
inspection, it seems like the 0 size comes from the fb_probe path? Is there
somewhere in the helpers that you could check the mode is sane so all drivers
can benefit?
Sean
>
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> ---
>
> drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
> index df9e570..8917922 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
> @@ -315,6 +315,11 @@ struct rockchip_gem_object *
> struct drm_gem_object *obj;
> int ret;
>
> + if (!size) {
> + DRM_ERROR("gem buffer size is zero\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> size = round_up(size, PAGE_SIZE);
>
> rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
> --
> 2.1.4
>
--
Sean Paul, Software Engineer, Google / Chromium OS
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/rockchip: Don't allow zero sized gem buffer
2017-05-25 15:30 ` Sean Paul
@ 2017-05-26 2:30 ` jeffy
2017-05-26 5:52 ` Christoph Hellwig
2017-05-26 13:49 ` Sean Paul
0 siblings, 2 replies; 6+ messages in thread
From: jeffy @ 2017-05-26 2:30 UTC (permalink / raw)
To: Sean Paul
Cc: linux-kernel, tfiga, Mark Yao, Heiko Stuebner, dri-devel,
linux-rockchip, David Airlie, linux-arm-kernel
Hi sean,
On 05/25/2017 11:30 PM, Sean Paul wrote:
> On Tue, May 23, 2017 at 02:39:43PM +0800, Jeffy Chen wrote:
>> The system would crash when trying to alloc zero sized gem buffer:
>> [ 6.712435] Unable to handle kernel NULL pointer dereference at virtual address 00000010 <--ZERO_SIZE_PTR
>> ...
>> [ 6.757502] PC is at sg_alloc_table_from_pages+0x170/0x1ec
>
> It's unfortunate that you didn't include the entire stack trace. From code
> inspection, it seems like the 0 size comes from the fb_probe path? Is there
> somewhere in the helpers that you could check the mode is sane so all drivers
> can benefit?
hmm, sorry, i was testing it on chromeos 4.4 kernel, it turns out that
we have a custom ioctl for userspace to create gem buffer(the same as
exynos drm), which might get the the 0 size.
but on upstream kernel, it could only be called by dump_create, and the
drm_mode_create_dumb_ioctl already did the size check.
will resent this patch, and rewrite the commit message, thanx.
>
> Sean
>
>>
>> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
>> ---
>>
>> drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>> index df9e570..8917922 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>> @@ -315,6 +315,11 @@ struct rockchip_gem_object *
>> struct drm_gem_object *obj;
>> int ret;
>>
>> + if (!size) {
>> + DRM_ERROR("gem buffer size is zero\n");
>> + return ERR_PTR(-EINVAL);
>> + }
>> +
>> size = round_up(size, PAGE_SIZE);
>>
>> rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
>> --
>> 2.1.4
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/rockchip: Don't allow zero sized gem buffer
2017-05-26 2:30 ` jeffy
@ 2017-05-26 5:52 ` Christoph Hellwig
2017-05-26 6:50 ` Daniel Vetter
2017-05-26 13:49 ` Sean Paul
1 sibling, 1 reply; 6+ messages in thread
From: Christoph Hellwig @ 2017-05-26 5:52 UTC (permalink / raw)
To: jeffy
Cc: Sean Paul, linux-kernel, tfiga, Mark Yao, Heiko Stuebner,
dri-devel, linux-rockchip, David Airlie, linux-arm-kernel
On Fri, May 26, 2017 at 10:30:09AM +0800, jeffy wrote:
> Hi sean,
>
> On 05/25/2017 11:30 PM, Sean Paul wrote:
> > On Tue, May 23, 2017 at 02:39:43PM +0800, Jeffy Chen wrote:
> > > The system would crash when trying to alloc zero sized gem buffer:
> > > [ 6.712435] Unable to handle kernel NULL pointer dereference at virtual address 00000010 <--ZERO_SIZE_PTR
> > > ...
> > > [ 6.757502] PC is at sg_alloc_table_from_pages+0x170/0x1ec
> >
> > It's unfortunate that you didn't include the entire stack trace. From code
> > inspection, it seems like the 0 size comes from the fb_probe path? Is there
> > somewhere in the helpers that you could check the mode is sane so all drivers
> > can benefit?
>
> hmm, sorry, i was testing it on chromeos 4.4 kernel, it turns out that we
> have a custom ioctl for userspace to create gem buffer(the same as exynos
> drm), which might get the the 0 size.
>
> but on upstream kernel, it could only be called by dump_create, and the
> drm_mode_create_dumb_ioctl already did the size check.
>
> will resent this patch, and rewrite the commit message, thanx.
That suggests that this patch isn't needed at all.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/rockchip: Don't allow zero sized gem buffer
2017-05-26 5:52 ` Christoph Hellwig
@ 2017-05-26 6:50 ` Daniel Vetter
0 siblings, 0 replies; 6+ messages in thread
From: Daniel Vetter @ 2017-05-26 6:50 UTC (permalink / raw)
To: Christoph Hellwig
Cc: jeffy, Linux Kernel Mailing List, dri-devel, Tomasz Figa,
open list:ARM/Rockchip SoC...,
linux-arm-kernel
On Fri, May 26, 2017 at 7:52 AM, Christoph Hellwig <hch@infradead.org> wrote:
> On Fri, May 26, 2017 at 10:30:09AM +0800, jeffy wrote:
>> Hi sean,
>>
>> On 05/25/2017 11:30 PM, Sean Paul wrote:
>> > On Tue, May 23, 2017 at 02:39:43PM +0800, Jeffy Chen wrote:
>> > > The system would crash when trying to alloc zero sized gem buffer:
>> > > [ 6.712435] Unable to handle kernel NULL pointer dereference at virtual address 00000010 <--ZERO_SIZE_PTR
>> > > ...
>> > > [ 6.757502] PC is at sg_alloc_table_from_pages+0x170/0x1ec
>> >
>> > It's unfortunate that you didn't include the entire stack trace. From code
>> > inspection, it seems like the 0 size comes from the fb_probe path? Is there
>> > somewhere in the helpers that you could check the mode is sane so all drivers
>> > can benefit?
>>
>> hmm, sorry, i was testing it on chromeos 4.4 kernel, it turns out that we
>> have a custom ioctl for userspace to create gem buffer(the same as exynos
>> drm), which might get the the 0 size.
>>
>> but on upstream kernel, it could only be called by dump_create, and the
>> drm_mode_create_dumb_ioctl already did the size check.
>>
>> will resent this patch, and rewrite the commit message, thanx.
>
> That suggests that this patch isn't needed at all.
Yes, not needed for upstream. But next time around pls include the
entire backtrace (or at least the relevant parts), not just the last
line, so that we can figure this out directly.
Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drm/rockchip: Don't allow zero sized gem buffer
2017-05-26 2:30 ` jeffy
2017-05-26 5:52 ` Christoph Hellwig
@ 2017-05-26 13:49 ` Sean Paul
1 sibling, 0 replies; 6+ messages in thread
From: Sean Paul @ 2017-05-26 13:49 UTC (permalink / raw)
To: jeffy
Cc: Sean Paul, linux-kernel, tfiga, Mark Yao, Heiko Stuebner,
dri-devel, linux-rockchip, David Airlie, linux-arm-kernel
On Fri, May 26, 2017 at 10:30:09AM +0800, jeffy wrote:
> Hi sean,
>
> On 05/25/2017 11:30 PM, Sean Paul wrote:
> > On Tue, May 23, 2017 at 02:39:43PM +0800, Jeffy Chen wrote:
> > > The system would crash when trying to alloc zero sized gem buffer:
> > > [ 6.712435] Unable to handle kernel NULL pointer dereference at virtual address 00000010 <--ZERO_SIZE_PTR
> > > ...
> > > [ 6.757502] PC is at sg_alloc_table_from_pages+0x170/0x1ec
> >
> > It's unfortunate that you didn't include the entire stack trace. From code
> > inspection, it seems like the 0 size comes from the fb_probe path? Is there
> > somewhere in the helpers that you could check the mode is sane so all drivers
> > can benefit?
>
> hmm, sorry, i was testing it on chromeos 4.4 kernel, it turns out that we
> have a custom ioctl for userspace to create gem buffer(the same as exynos
> drm), which might get the the 0 size.
>
> but on upstream kernel, it could only be called by dump_create, and the
> drm_mode_create_dumb_ioctl already did the size check.
Ah, ok. In that case, fix the custom ioctl such that it ensures we never call
this function with size == 0, and upload it downstream with a CHROMIUM prefix.
Sean
>
> will resent this patch, and rewrite the commit message, thanx.
>
> >
> > Sean
> >
> > >
> > > Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> > > ---
> > >
> > > drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++++
> > > 1 file changed, 5 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
> > > index df9e570..8917922 100644
> > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
> > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
> > > @@ -315,6 +315,11 @@ struct rockchip_gem_object *
> > > struct drm_gem_object *obj;
> > > int ret;
> > >
> > > + if (!size) {
> > > + DRM_ERROR("gem buffer size is zero\n");
> > > + return ERR_PTR(-EINVAL);
> > > + }
> > > +
> > > size = round_up(size, PAGE_SIZE);
> > >
> > > rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
> > > --
> > > 2.1.4
> > >
> >
>
--
Sean Paul, Software Engineer, Google / Chromium OS
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-05-26 13:50 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-05-23 6:39 [PATCH] drm/rockchip: Don't allow zero sized gem buffer Jeffy Chen
2017-05-25 15:30 ` Sean Paul
2017-05-26 2:30 ` jeffy
2017-05-26 5:52 ` Christoph Hellwig
2017-05-26 6:50 ` Daniel Vetter
2017-05-26 13:49 ` Sean Paul
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