3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chris Wilson <ch...@chris-wilson.co.uk>
commit b062672e305ce071f21eb9e18b102c2a430e0999 upstream.
Apply the protections from
commit 1b2f1489633888d4a06028315dc19d65768a1c05
Author: Dave Airlie <airlied at redhat.com>
Date: Sat Aug 14 20:20:34 2010 +1000
drm: block userspace under allocating buffer and having drivers overwrite
it (v2)
to the core ioctl structs as well, for we found one instance where there
is a 32-/64-bit size mismatch and were guilty of writing beyond the end
of the user's buffer.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Dave Airlie <airlied at redhat.com>
Reviewed-by: Ville Syrj?l? <ville.syrjala at linux.intel.com>
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Dave Airlie <airlied at redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
drivers/gpu/drm/drm_drv.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -420,9 +420,16 @@ long drm_ioctl(struct file *filp,
asize = drv_size;
}
else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
+ u32 drv_size;
+
ioctl = &drm_ioctls[nr];
- cmd = ioctl->cmd;
+
+ drv_size = _IOC_SIZE(ioctl->cmd);
usize = asize = _IOC_SIZE(cmd);
+ if (drv_size > asize)
+ asize = drv_size;
+
+ cmd = ioctl->cmd;
} else
goto err_i1;
