Re: [PATCH next] udmabuf: fix general protection fault in udmabuf_create

[Gerd Hoffmann]

On Wed, Aug 11, 2021 at 08:50:52PM +0300, Pavel Skripkin wrote:
> Syzbot reported general protection fault in udmabuf_create. The problem
> was in wrong error handling.
> 
> In commit 16c243e99d33 ("udmabuf: Add support for mapping hugepages (v4)")
> shmem_read_mapping_page() call was replaced with find_get_page_flags(),
> but find_get_page_flags() returns NULL on failure instead PTR_ERR().
> 
> Wrong error checking was causing GPF in get_page(), since passed page
> was equal to NULL. Fix it by changing if (IS_ER(!hpage)) to if (!hpage)
> 
> Reported-by: syzbot+e9cd3122a37c5d6c51e8@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 16c243e99d33 ("udmabuf: Add support for mapping hugepages (v4)")
> Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>

Pushed to drm-misc-next.

thanks,
  Gerd