Commit 7e700d2c authored May 31, 2017 by Prarit Bhargava Committed by Dan Williams Jul 17, 2017

acpi/nfit: Fix memory corruption/Unregister mce decoder on failure



nfit_init() calls nfit_mce_register() on module load.  When the module
load fails the nfit mce decoder is not unregistered.  The module's
memory is freed leaving the decoder chain referencing junk.  This will
cause panics as future registrations will reference the free'd memory.

Unregister the nfit mce decoder on module init failure.

[v2]: register and then unregister mce handler to avoid losing mce events
[v3]: also cleanup nfit workqueue

Fixes: 6839a6d9 ("nfit: do an ARS scrub on hitting a latent media error")
Cc: <stable@vger.kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Lee, Chun-Yi" <joeyli.kernel@gmail.com>
Cc: Linda Knippers <linda.knippers@hpe.com>
Cc: lszubowi@redhat.com
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent 43fe51e1

drivers/acpi/nfit/core.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -3160,6 +3160,8 @@ static struct acpi_driver acpi_nfit_driver = {

		static __init int nfit_init(void)
		{
		int ret;

		BUILD_BUG_ON(sizeof(struct acpi_table_nfit) != 40);
		BUILD_BUG_ON(sizeof(struct acpi_nfit_system_address) != 56);
		BUILD_BUG_ON(sizeof(struct acpi_nfit_memory_map) != 48);
		@@ -3187,8 +3189,14 @@ static __init int nfit_init(void)
		return -ENOMEM;

		nfit_mce_register();
		ret = acpi_bus_register_driver(&acpi_nfit_driver);
		if (ret) {
		nfit_mce_unregister();
		destroy_workqueue(nfit_wq);
		}

		return ret;

		return acpi_bus_register_driver(&acpi_nfit_driver);
		}

		static __exit void nfit_exit(void)

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