From: Daniel Vetter <daniel@ffwll.ch>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: patrik.r.jakobsson@gmail.com, airlied@linux.ie, daniel@ffwll.ch,
dri-devel@lists.freedesktop.org, Alan Cox <alan@linux.intel.com>,
Dave Airlie <airlied@redhat.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] drm/gma500: Fix out-of-bounds access to struct drm_device.vblank[]
Date: Thu, 5 Nov 2020 20:21:33 +0100 [thread overview]
Message-ID: <20201105192133.GD401619@phenom.ffwll.local> (raw)
In-Reply-To: <20201105190256.3893-1-tzimmermann@suse.de>
On Thu, Nov 05, 2020 at 08:02:56PM +0100, Thomas Zimmermann wrote:
> The gma500 driver expects 3 pipelines in several it's IRQ functions.
> Accessing struct drm_device.vblank[], this fails with devices that only
> have 2 pipelines. An example KASAN report is shown below.
>
> [ 62.267688] ==================================================================
> [ 62.268856] BUG: KASAN: slab-out-of-bounds in psb_irq_postinstall+0x250/0x3c0 [gma500_gfx]
> [ 62.269450] Read of size 1 at addr ffff8880012bc6d0 by task systemd-udevd/285
> [ 62.269949]
> [ 62.270192] CPU: 0 PID: 285 Comm: systemd-udevd Tainted: G E 5.10.0-rc1-1-default+ #572
> [ 62.270807] Hardware name: /DN2800MT, BIOS MTCDT10N.86A.0164.2012.1213.1024 12/13/2012
> [ 62.271366] Call Trace:
> [ 62.271705] dump_stack+0xae/0xe5
> [ 62.272180] print_address_description.constprop.0+0x17/0xf0
> [ 62.272987] ? psb_irq_postinstall+0x250/0x3c0 [gma500_gfx]
> [ 62.273474] __kasan_report.cold+0x20/0x38
> [ 62.273989] ? psb_irq_postinstall+0x250/0x3c0 [gma500_gfx]
> [ 62.274460] kasan_report+0x3a/0x50
> [ 62.274891] psb_irq_postinstall+0x250/0x3c0 [gma500_gfx]
> [ 62.275380] drm_irq_install+0x131/0x1f0
> <...>
> [ 62.300751] Allocated by task 285:
> [ 62.301223] kasan_save_stack+0x1b/0x40
> [ 62.301731] __kasan_kmalloc.constprop.0+0xbf/0xd0
> [ 62.302293] drmm_kmalloc+0x55/0x100
> [ 62.302773] drm_vblank_init+0x77/0x210
>
> Resolve the issue by only handling vblank entries up to the number of
> CRTCs.
>
> I'm adding a Fixes tag for reference, although the bug has been present
> since the driver's initial commit.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: 5c49fd3aa0ab ("gma500: Add the core DRM files and headers")
> Cc: Alan Cox <alan@linux.intel.com>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: stable@vger.kernel.org#v3.3+
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
> drivers/gpu/drm/gma500/psb_irq.c | 34 +++++++++++---------------------
> 1 file changed, 12 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/gma500/psb_irq.c b/drivers/gpu/drm/gma500/psb_irq.c
> index 15eb3770d817..361e3a0c5ab6 100644
> --- a/drivers/gpu/drm/gma500/psb_irq.c
> +++ b/drivers/gpu/drm/gma500/psb_irq.c
> @@ -347,6 +347,7 @@ int psb_irq_postinstall(struct drm_device *dev)
> {
> struct drm_psb_private *dev_priv = dev->dev_private;
> unsigned long irqflags;
> + unsigned int i;
>
> spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
>
> @@ -359,20 +360,12 @@ int psb_irq_postinstall(struct drm_device *dev)
> PSB_WVDC32(dev_priv->vdc_irq_mask, PSB_INT_ENABLE_R);
> PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
>
> - if (dev->vblank[0].enabled)
> - psb_enable_pipestat(dev_priv, 0, PIPE_VBLANK_INTERRUPT_ENABLE);
> - else
> - psb_disable_pipestat(dev_priv, 0, PIPE_VBLANK_INTERRUPT_ENABLE);
> -
> - if (dev->vblank[1].enabled)
> - psb_enable_pipestat(dev_priv, 1, PIPE_VBLANK_INTERRUPT_ENABLE);
> - else
> - psb_disable_pipestat(dev_priv, 1, PIPE_VBLANK_INTERRUPT_ENABLE);
> -
> - if (dev->vblank[2].enabled)
> - psb_enable_pipestat(dev_priv, 2, PIPE_VBLANK_INTERRUPT_ENABLE);
> - else
> - psb_disable_pipestat(dev_priv, 2, PIPE_VBLANK_INTERRUPT_ENABLE);
> + for (i = 0; i < dev->num_crtcs; ++i) {
> + if (dev->vblank[i].enabled)
> + psb_enable_pipestat(dev_priv, i, PIPE_VBLANK_INTERRUPT_ENABLE);
> + else
> + psb_disable_pipestat(dev_priv, i, PIPE_VBLANK_INTERRUPT_ENABLE);
> + }
>
> if (dev_priv->ops->hotplug_enable)
> dev_priv->ops->hotplug_enable(dev, true);
> @@ -385,6 +378,7 @@ void psb_irq_uninstall(struct drm_device *dev)
> {
> struct drm_psb_private *dev_priv = dev->dev_private;
> unsigned long irqflags;
> + unsigned int i;
>
> spin_lock_irqsave(&dev_priv->irqmask_lock, irqflags);
>
> @@ -393,14 +387,10 @@ void psb_irq_uninstall(struct drm_device *dev)
>
> PSB_WVDC32(0xFFFFFFFF, PSB_HWSTAM);
>
> - if (dev->vblank[0].enabled)
> - psb_disable_pipestat(dev_priv, 0, PIPE_VBLANK_INTERRUPT_ENABLE);
> -
> - if (dev->vblank[1].enabled)
> - psb_disable_pipestat(dev_priv, 1, PIPE_VBLANK_INTERRUPT_ENABLE);
> -
> - if (dev->vblank[2].enabled)
> - psb_disable_pipestat(dev_priv, 2, PIPE_VBLANK_INTERRUPT_ENABLE);
> + for (i = 0; i < dev->num_crtcs; ++i) {
> + if (dev->vblank[i].enabled)
> + psb_disable_pipestat(dev_priv, i, PIPE_VBLANK_INTERRUPT_ENABLE);
> + }
>
> dev_priv->vdc_irq_mask &= _PSB_IRQ_SGX_FLAG |
> _PSB_IRQ_MSVDX_FLAG |
> --
> 2.29.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
prev parent reply other threads:[~2020-11-05 19:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 19:02 [PATCH] drm/gma500: Fix out-of-bounds access to struct drm_device.vblank[] Thomas Zimmermann
2020-11-05 19:21 ` Daniel Vetter [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201105192133.GD401619@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=airlied@linux.ie \
--cc=airlied@redhat.com \
--cc=alan@linux.intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=patrik.r.jakobsson@gmail.com \
--cc=stable@vger.kernel.org \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).