linux-kernel - Re: [Bug #13780] NULL pointer dereference loading powernowk8

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:	Tue, 15 Sep 2009 16:45:37 -0700 (PDT)
From:	David Rientjes <rientjes@...gle.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
cc:	Kurt Roeckx <kurt@...ckx.be>, Dave Jones <davej@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Kernel Testers <kernel-testers@...r.kernel.org>,
	Mark Langsdorf <mark.langsdorf@....com>,
	Naga Chumbalkar <nagananda.chumbalkar@...com>
Subject: Re: [Bug #13780] NULL pointer dereference loading powernowk8

On Thu, 10 Sep 2009, Rafael J. Wysocki wrote:

> > So I did a biset, and this is the result:
> > $ git bisect good
> > 0e64a0c982c06a6b8f5e2a7f29eb108fdf257b2f is first bad commit
> > commit 0e64a0c982c06a6b8f5e2a7f29eb108fdf257b2f
> > Author: Dave Jones <davej@...hat.com>
> > Date:   Wed Feb 4 14:37:50 2009 -0500
> > 
> >     [CPUFREQ] checkpatch cleanups for powernow-k8
> > 
> >     This driver has so many long function names, and deep nested if's
> >     The remaining warnings will need some code restructuring to clean up.
> > 
> >     Signed-off-by: Dave Jones <davej@...hat.com>
> > 
> > :040000 040000 45d8e325663e62e0833cf4e1cb8b27fa4a9b3a56 affb6fab44cb22aca8a33ca0d767797831fc2bae M      arch
> > 
> > 2.6.29-rc5 is good, -rc7 is bad.
> 
> Thanks for the update and for doing the bisection.
> 

0e64a0c has this cleanup, which isn't equivalent to the previous code:

@@ -779,11 +834,12 @@ static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
 		goto err_out;
 	}
 
-	if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
-		(data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
+	space_id = data->acpi_data.control_register.space_id;
+	if ((space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
+		(space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
 		dprintk("Invalid control/status registers (%x - %x)\n",
 			data->acpi_data.control_register.space_id,
-			data->acpi_data.status_register.space_id);
+			space_id);
 		goto err_out;
 	}
 
This got fixed in 2c701b1 in 2.6.31-rc8, so this is most likely the 
problem that Kurt was encountering.

Kurt, could you try 2.6.31 and see if you still experience the issue?  If 
not, this can be closed.
--
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/