commit 06ad8d3395 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: 5c49fd3aa0 ("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-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
c6a6168a31