| From | Ben Hutchings <> | Date | Sun, 16 Jul 2017 14:56:38 +0100 | Subject | [PATCH 3.2 56/95] drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() |
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3.2.91-rc1 review patch. If anyone has any objections, please let me know.
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From: Murray McAllister <murray.mcallister@insomniasec.com>
commit 63774069d9527a1aeaa4aa20e929ef5e8e9ecc38 upstream.
In vmw_get_cap_3d_ioctl(), a user can supply 0 for a size that is used in vzalloc(). This eventually calls dump_stack() (in warn_alloc()), which can leak useful addresses to dmesg.
Add check to avoid a size of 0.
Signed-off-by: Murray McAllister <murray.mcallister@insomniasec.com> Reviewed-by: Sinclair Yeh <syeh@vmware.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c @@ -90,7 +90,7 @@ int vmw_get_cap_3d_ioctl(struct drm_devi void *bounce; int ret; - if (unlikely(arg->pad64 != 0)) { + if (unlikely(arg->pad64 != 0 || arg->max_size == 0)) { DRM_ERROR("Illegal GET_3D_CAP argument.\n"); return -EINVAL; }
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