drm/shmem-helper: Remove errant put in error path

drm_gem_shmem_mmap() doesn't own this reference, resulting in the GEM
object getting prematurely freed leading to a later use-after-free.

Link: https://syzkaller.appspot.com/bug?extid=c8ae65286134dd1b800d
Reported-by: syzbot+c8ae65286134dd1b800d@syzkaller.appspotmail.com
Fixes: 2194a63a81 ("drm: Add library for shmem backed GEM objects")
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221130185748.357410-2-robdclark@gmail.com
This commit is contained in:
Rob Clark 2022-11-30 10:57:47 -08:00 committed by Javier Martinez Canillas
parent d3d6b1bf85
commit 24013314be
No known key found for this signature in database
GPG Key ID: C751E590D63F3D69

View File

@ -622,10 +622,8 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
}
ret = drm_gem_shmem_get_pages(shmem);
if (ret) {
drm_gem_vm_close(vma);
if (ret)
return ret;
}
vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);