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authorZack Rusin <zackr@vmware.com>2021-12-15 15:02:24 -0500
committerThomas Zimmermann <tzimmermann@suse.de>2021-12-17 16:35:30 +0100
commit58fa0d90eddeda37b32597eda139e888ebe5af04 (patch)
tree9348b3eeee3997deb71ddec6680bf674c3fd36ae
parentdrm/vmwgfx: Remove unused compile options (diff)
downloadlinux-dev-58fa0d90eddeda37b32597eda139e888ebe5af04.tar.xz
linux-dev-58fa0d90eddeda37b32597eda139e888ebe5af04.zip
drm/vmwgfx: Fix possible usage of an uninitialized variable
vmw_user_bo_lookup can fail to lookup user buffers, especially because the buffer handles come from the userspace. The return value has to be checked before the buffers are put back. This was spotted by Dan's Smatch statick checker: drivers/gpu/drm/vmwgfx/vmwgfx_bo.c:574 vmw_user_bo_synccpu_release() error: uninitialized symbol 'vmw_bo'. Signed-off-by: Zack Rusin <zackr@vmware.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 8afa13a0583f ("drm/vmwgfx: Implement DRIVER_GEM") Reviewed-by: Martin Krastev <krastevm@vmware.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211215200224.3693345-1-zack@kde.org (cherry picked from commit 60c9ecd705be3a28f79d70ea21c3939db668bf46) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
-rw-r--r--drivers/gpu/drm/vmwgfx/vmwgfx_bo.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index 15fead85450c..31aecc46624b 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -568,10 +568,12 @@ static int vmw_user_bo_synccpu_release(struct drm_file *filp,
struct vmw_buffer_object *vmw_bo;
int ret = vmw_user_bo_lookup(filp, handle, &vmw_bo);
- if (!(flags & drm_vmw_synccpu_allow_cs)) {
- atomic_dec(&vmw_bo->cpu_writers);
+ if (!ret) {
+ if (!(flags & drm_vmw_synccpu_allow_cs)) {
+ atomic_dec(&vmw_bo->cpu_writers);
+ }
+ ttm_bo_put(&vmw_bo->base);
}
- ttm_bo_put(&vmw_bo->base);
return ret;
}