Re: [PATCH] cifs: Fix signature miscalculation

[Tom Talpey]

Ouch! Thanks for this, and just in time for next week's IOLab. :)

Reviewed-by: Tom Talpey <tom@xxxxxxxxxx>

Tom.

On 9/12/2024 12:24 PM, Steve French wrote:
> looks like this fixes the problem - merged into cifs-2.6.git for-next
>
> On Thu, Sep 12, 2024 at 10:59 AM David Howells <dhowells@xxxxxxxxxx> wrote:
> > Fix the calculation of packet signatures by adding the offset into a page
> > in the read or write data payload when hashing the pages from it.
> >
> > Fixes: 39bc58203f04 ("cifs: Add a function to Hash the contents of an iterator")
> > Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> > cc: Steve French <sfrench@xxxxxxxxx>
> > cc: Paulo Alcantara <pc@xxxxxxxxxxxxx>
> > cc: Shyam Prasad N <nspmangalore@xxxxxxxxx>
> > cc: Rohith Surabattula <rohiths.msft@xxxxxxxxx>
> > cc: Jeff Layton <jlayton@xxxxxxxxxx>
> > cc: linux-cifs@xxxxxxxxxxxxxxx
> > cc: linux-fsdevel@xxxxxxxxxxxxxxx
> > ---
> >   fs/smb/client/cifsencrypt.c |    2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/smb/client/cifsencrypt.c b/fs/smb/client/cifsencrypt.c
> > index 6322f0f68a17..b0473c2567fe 100644
> > --- a/fs/smb/client/cifsencrypt.c
> > +++ b/fs/smb/client/cifsencrypt.c
> > @@ -129,7 +129,7 @@ static ssize_t cifs_shash_xarray(const struct iov_iter *iter, ssize_t maxsize,
> >                          for (j = foffset / PAGE_SIZE; j < npages; j++) {
> >                                  len = min_t(size_t, maxsize, PAGE_SIZE - offset);
> >                                  p = kmap_local_page(folio_page(folio, j));
> > -                               ret = crypto_shash_update(shash, p, len);
> > +                               ret = crypto_shash_update(shash, p + offset, len);
> >                                  kunmap_local(p);
> >                                  if (ret < 0)
> >                                          return ret;