Re: [PATCH] fsl/fman: Add array size check

[Sean Anderson]

On 3/7/24 03:04, Aleksandr Mishin wrote:
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>
> In fman_register_intr() and fman_unregister_intr()
> get_module_event() is assigned to event which is then used
> as array index without size check.
> Fix this bug by adding a check of event.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: 414fd46e7762 (fsl/fman: Add FMan support)
> Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/freescale/fman/fman.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fman/fman.c b/drivers/net/ethernet/freescale/fman/fman.c
> index d96028f01770..902d05ffff1b 100644
> --- a/drivers/net/ethernet/freescale/fman/fman.c
> +++ b/drivers/net/ethernet/freescale/fman/fman.c
> @@ -2054,7 +2054,10 @@ void fman_register_intr(struct fman *fman, enum fman_event_modules module,
>         int event = 0;
>
>         event = get_module_event(module, mod_id, intr_type);
> -       WARN_ON(event >= FMAN_EV_CNT);
> +       if (event >= FMAN_EV_CNT) {
> +               WARN_ON(event >= FMAN_EV_CNT);
> +               return;
> +       }
>
>         /* register in local FM structure */
>         fman->intr_mng[event].isr_cb = isr_cb;
> @@ -2079,7 +2082,10 @@ void fman_unregister_intr(struct fman *fman, enum fman_event_modules module,
>         int event = 0;
>
>         event = get_module_event(module, mod_id, intr_type);
> -       WARN_ON(event >= FMAN_EV_CNT);
> +       if (event >= FMAN_EV_CNT) {
> +               WARN_ON(event >= FMAN_EV_CNT);
> +               return;
> +       }
>
>         fman->intr_mng[event].isr_cb = NULL;
>         fman->intr_mng[event].src_handle = NULL;
> --
> 2.30.2
>

Nack. This condition should never occur, that's why we have the WARN_ON.

--Sean

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