On Wed, 13 Sep 2023 16:22:28 +0300
Dmitry Frolov <frolov@swemel.ru> wrote:
> According to cxl_interleave_ways_enc(),
> fw->num_targets is allowed to be up to 16.
> This also corresponds to CXL specs.
> So, the fw->target_hbs[] array is iterated from 0 to 15.
> But it is staticaly declared of length 8.
> Thus, out of bound array access may occur.
>
> Fixes: c28db9e000 ("hw/pci-bridge: Make PCIe and CXL PXB Devices inherit from TYPE_PXB_DEV")
>
> Signed-off-by: Dmitry Frolov <frolov@swemel.ru>
> ---
> v2: assert added
> ---
> hw/cxl/cxl-host.c | 1 +
> include/hw/cxl/cxl.h | 2 +-
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c
> index 034c7805b3..fe9143409b 100644
> --- a/hw/cxl/cxl-host.c
> +++ b/hw/cxl/cxl-host.c
> @@ -33,6 +33,7 @@ static void cxl_fixed_memory_window_config(CXLState *cxl_state,
> for (target = object->targets; target; target = target->next) {
> fw->num_targets++;
> }
> + assert(fw->num_targets <= ARRAY_SIZE(fw->target_hbs));
Just incase it gets lost as I replied late to the v1 comment.
This is both unnecessary and results in an
assert for a case that would otherwise be a nice error message about unsupported
number of interleave ways.
Jonathan
>
> fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp);
> if (*errp) {
> diff --git a/include/hw/cxl/cxl.h b/include/hw/cxl/cxl.h
> index 56c9e7676e..4944725849 100644
> --- a/include/hw/cxl/cxl.h
> +++ b/include/hw/cxl/cxl.h
> @@ -29,7 +29,7 @@ typedef struct PXBCXLDev PXBCXLDev;
> typedef struct CXLFixedWindow {
> uint64_t size;
> char **targets;
> - PXBCXLDev *target_hbs[8];
> + PXBCXLDev *target_hbs[16];
> uint8_t num_targets;
> uint8_t enc_int_ways;
> uint8_t enc_int_gran;