linux-kernel - Re: [PATCH v3] clk: scmi: Handle case where child clocks are initialized before their parents

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20250613-congenial-tamarin-of-experience-cb2598@sudeepholla>
Date: Fri, 13 Jun 2025 14:43:35 +0100
From: Sudeep Holla <sudeep.holla@....com>
To: Sascha Hauer <s.hauer@...gutronix.de>
Cc: Cristian Marussi <cristian.marussi@....com>,
	Sudeep Holla <sudeep.holla@....com>,
	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>, Peng Fan <peng.fan@....com>,
	<arm-scmi@...r.kernel.org>, <linux-arm-kernel@...ts.infradead.org>,
	<linux-clk@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3] clk: scmi: Handle case where child clocks are
 initialized before their parents

On Thu, Jun 12, 2025 at 02:56:57PM +0200, Sascha Hauer wrote:
> The SCMI clock driver currently assumes that parent clocks are always
> initialized before their children. However, this assumption can fail if
> a child clock is encountered before its parent during probe.
> 
> This leads to an issue during initialization of the parent_data array:
> 
>     sclk->parent_data[i].hw = hws[sclk->info->parents[i]];
> 
> If the parent clock's hardware structure has not been initialized yet,
> this assignment results in invalid data.
> 
> To resolve this, allocate all struct scmi_clk instances as a contiguous
> array at the beginning of the probe and populate the hws[] array
> upfront. This ensures that any parent referenced later is already
> initialized, regardless of the order in which clocks are processed.
> 
> Note that we can no longer free individual scmi_clk instances if
> scmi_clk_ops_init() fails which shouldn't be a problem if the SCMI
> platform has proper per-agent clock discovery.
> 
> Fixes: 65a8a3dd3b95f ("clk: scmi: Add support for clock {set,get}_parent")
> Reviewed-by: peng.fan@....com
> Reviewed-by: Cristian Marussi <cristian.marussi@....com>
> Reviewed-by: Sudeep Holla <sudeep.holla@....com>

Mike/Stephen,

Please pick this up in your next round of fixes.

-- 
Regards,
Sudeep