Re: PROBLEM: Kernel oops when mounting a encryptData CIFS share with CONFIG_DEBUG_VIRTUAL

[Pavel Shilovsky <pavel.shilovsky@gmail.com>]

чт, 25 июл. 2019 г. в 09:57, Sebastien Tisserant via samba-technical
<samba-technical@lists.samba.org>:
...
>
> mount works without CONFIG_DEBUG_VIRTUAL
>
> If we don't set CONFIG_VMAP_STACK mount works with CONFIG_DEBUG_VIRTUAL
>
>
> We have the following (very quick and dirty) patch :
>
> Index: linux-4.19.60/fs/cifs/smb2ops.c
> ===================================================================
> --- linux-4.19.60.orig/fs/cifs/smb2ops.c
> +++ linux-4.19.60/fs/cifs/smb2ops.c
> @@ -2545,7 +2545,15 @@ fill_transform_hdr(struct smb2_transform
>  static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf,
>                     unsigned int buflen)
>  {
> -    sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
> +      void *addr;
> +      /*
> +       * VMAP_STACK (at least) puts stack into the vmalloc address space
> +      */
> +      if (is_vmalloc_addr(buf))
> +              addr = vmalloc_to_page(buf);
> +      else
> +              addr = virt_to_page(buf);
> +      sg_set_page(sg, addr, buflen, offset_in_page(buf));
>  }
>
>  /* Assumes the first rqst has a transform header as the first iov.
>
>

Thanks for reporting this. The patch looks good to me. Did you test
your scenario all together with it (not only mounting)?


Best regards,
Pavel Shilovskiy