From: Thomas Zimmermann tzimmermann@suse.de
commit 06ad8d339524bf94b89859047822c31df6ace239 upstream.
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 Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch 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+ Link: https://patchwork.freedesktop.org/patch/msgid/20201105190256.3893-1-tzimmerm... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/gma500/psb_irq.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-)
--- 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_devic { 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_devic 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 { 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
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 |