linux-kernel - Re: [PATCH] intel_idle: Check cpu_idle_get_driver() for NULL before dereferencing it.

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

Date:	Sat, 4 Aug 2012 23:56:35 +0200
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc:	lenb@...nel.org, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] intel_idle: Check cpu_idle_get_driver() for NULL before dereferencing it.

On Thursday, August 02, 2012, Konrad Rzeszutek Wilk wrote:
> If the machine is booted without any cpu_idle driver set
> (b/c disable_cpuidle() has been called) we should follow
> other users of cpu_idle API and check the return value
> for NULL before using it.
> 
> Reported-by: Mark van Dijk <mark@...ernecto.net>
> Tested-by: Mark van Dijk <mark@...ernecto.net>
> Suggested-by: Jan Beulich <JBeulich@...e.com>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
> ---
>  drivers/idle/intel_idle.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
> index f559088..7383aa0 100644
> --- a/drivers/idle/intel_idle.c
> +++ b/drivers/idle/intel_idle.c
> @@ -607,7 +607,7 @@ static int __init intel_idle_init(void)
>  	retval = cpuidle_register_driver(&intel_idle_driver);
>  	if (retval) {

What about:

  		struct cpuidle_driver *drv = cpuidle_get_driver();

  		printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
			drv ? drv->name : "none");

>  		printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
> -			cpuidle_get_driver()->name);
> +			cpuidle_get_driver() ? cpuidle_get_driver()->name : "none");
>  		return retval;
>  	}
>  
> 

Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/