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

[Steve French]

Sebastien,
I cleaned up the patch and merged into cifs-2.6.git - can you
doublecheck it is correct?


On Thu, Jul 25, 2019 at 3:35 PM Pavel Shilovsky
<pavel.shilovsky at gmail.com> wrote:
>
> чт, 25 июл. 2019 г. в 09:57, Sebastien Tisserant via samba-technical
> <samba-technical at 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



-- 
Thanks,

Steve
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