Re: [PATCH v2] clk: Sanitize possible_parent_show to Handle Return Value of of_clk_get_parent_name

From: Stephen Boyd
Date: Thu Oct 12 2023 - 19:22:03 EST


Quoting Alessandro Carminati (Red Hat) (2023-09-21 00:32:17)
> From: Alessandro Carminati <alessandro.carminati@xxxxxxxxx>
>
> In the possible_parent_show function, ensure proper handling of the return
> value from of_clk_get_parent_name to prevent potential issues arising from
> a NULL return.
> The current implementation invokes seq_puts directly on the result of
> of_clk_get_parent_name without verifying the return value, which can lead
> to kernel panic if the function returns NULL.
>
> This patch addresses the concern by introducing a check on the return
> value of of_clk_get_parent_name. If the return value is not NULL, the
> function proceeds to call seq_puts, providing the returned value as
> argument.
> However, if of_clk_get_parent_name returns NULL, the function provides a
> static string as argument, avoiding the panic.
>
> Fixes: 1ccc0ddf046a ("clk: Use seq_puts() in possible_parent_show()")
> Reported-by: Philip Daly <pdaly@xxxxxxxxxx>
> Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati@xxxxxxxxx>
> ---

Applied to clk-fixes