| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 82/84] ACPI / APEI: Add missing synchronize_rcu() on NOTIFY_SCI removal | Date | Mon, 28 Aug 2017 10:05:47 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: James Morse <james.morse@arm.com>
commit 7d64f82cceb21e6d95db312d284f5f195e120154 upstream.
When removing a GHES device notified by SCI, list_del_rcu() is used, ghes_remove() should call synchronize_rcu() before it goes on to call kfree(ghes), otherwise concurrent RCU readers may still hold this list entry after it has been freed.
Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Fixes: 81e88fdc432a (ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/acpi/apei/ghes.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -1072,6 +1072,7 @@ static int ghes_remove(struct platform_d if (list_empty(&ghes_sci)) unregister_acpi_hed_notifier(&ghes_notifier_sci); mutex_unlock(&ghes_list_mutex); + synchronize_rcu(); break; case ACPI_HEST_NOTIFY_NMI: ghes_nmi_remove(ghes);
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