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Patch "ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data" has been added to the 4.7-stable tree

PATCH [email protected] 1 participant 1 message Sep 2, 2016

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This is a note to let you know that I've just added the patch titled

ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
acpi-cppc-prevent-cpc_desc_ptr-points-to-the-invalid-data.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 2324d15447a9db168b1f85e3feac635b1ff8edb8 Mon Sep 17 00:00:00 2001

From: Hoan Tran <[email protected]>
Date: Wed, 25 May 2016 12:09:23 -0700
Subject: ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data

From: Hoan Tran <[email protected]>

commit 2324d15447a9db168b1f85e3feac635b1ff8edb8 upstream.

When CPPC fails to request a PCC channel, the CPC data is freed and cpc_desc_ptr points to the invalid data.

Avoid this issue by moving the cpc_desc_ptr assignment after the PCC channel request.

---
 drivers/acpi/cppc_acpi.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
drivers/acpi/cppc_acpi.c +3 -3
@@ -601,9 +601,6 @@ int acpi_cppc_processor_probe(struct acp
 	/* Store CPU Logical ID */
 	cpc_ptr->cpu_id = pr->id;
 
-	/* Plug it into this CPUs CPC descriptor. */
-	per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr;
-
 	/* Parse PSD data for this CPU */
 	ret = acpi_get_psd(cpc_ptr, handle);
 	if (ret)
@@ -616,6 +613,9 @@ int acpi_cppc_processor_probe(struct acp
 			goto out_free;
 	}
 
+	/* Plug PSD data into this CPUs CPC descriptor. */
+	per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr;
+
 	/* Everything looks okay */
 	pr_debug("Parsed CPC struct for CPU: %d\n", pr->id);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/acpi-cppc-return-error-if-_cpc-is-invalid-on-a-cpu.patch queue-4.7/acpi-cppc-prevent-cpc_desc_ptr-points-to-the-invalid-data.patch