Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.4 25/26] drm: Prevent overwriting from userspace underallocating core ioctl structs | Date | Fri, 8 Nov 2013 22:51:54 -0800 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Chris Wilson <chris@chris-wilson.co.uk>
commit b062672e305ce071f21eb9e18b102c2a430e0999 upstream.
Apply the protections from
commit 1b2f1489633888d4a06028315dc19d65768a1c05 Author: Dave Airlie <airlied@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@chris-wilson.co.uk> Cc: Dave Airlie <airlied@redhat.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: dri-devel@lists.freedesktop.org Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@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;
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