Re: [PATCH] vfio: Fix smatch errors in vfio_combine_iova_ranges()

[Jason Gunthorpe]

On Mon, Oct 02, 2023 at 04:43:25PM -0600, Alex Williamson wrote:
> smatch reports:
> 
> vfio_combine_iova_ranges() error: uninitialized symbol 'last'.
> vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_end'.
> vfio_combine_iova_ranges() error: potentially dereferencing uninitialized 'comb_start'.
> 
> These errors are only reachable via invalid input, in the case of
> @last when we receive an empty rb-tree or for @comb_{start,end} if the
> rb-tree is empty or otherwise fails to produce a second node that
> reduces the gap.  Add tests with warnings for these cases.
> 
> Reported-by: Cong Liu <liucong2@xxxxxxxxxx>
> Link: https://lore.kernel.org/all/20230920095532.88135-1-liucong2@xxxxxxxxxx
> Cc: Yishai Hadas <yishaih@xxxxxxxxxx>
> Cc: Brett Creeley <brett.creeley@xxxxxxx>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> ---
>  drivers/vfio/vfio_main.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Yeah, this is much clearer

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Thanks,
Jason