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authorPuneet Kumar <puneetster@chromium.org>2013-11-15 23:41:29 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-29 22:42:16 +0400
commit2e1219d642c41885b82bfba2e636603c04747a28 (patch)
treead6458f4efe4b8d89a1bdece19774048a01310af
parentb8d125faff42139ad14da49479d903ab696a009e (diff)
downloadlinux-2e1219d642c41885b82bfba2e636603c04747a28.tar.xz
ACPI / EC: Ensure lock is acquired before accessing ec struct members
commit 36b15875a7819a2ec4cb5748ff7096ad7bd86cbb upstream. A bug was introduced by commit b76b51ba0cef ('ACPI / EC: Add more debug info and trivial code cleanup') that erroneously caused the struct member to be accessed before acquiring the required lock. This change fixes it by ensuring the lock acquisition is done first. Found by Aaron Durbin <adurbin@chromium.org> Fixes: b76b51ba0cef ('ACPI / EC: Add more debug info and trivial code cleanup') References: http://crbug.com/319019 Signed-off-by: Puneet Kumar <puneetster@chromium.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> [olof: Commit message reworded a bit] Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/acpi/ec.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 45af90a1ec1b..1ad5a4f9e0c3 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -175,9 +175,10 @@ static void start_transaction(struct acpi_ec *ec)
static void advance_transaction(struct acpi_ec *ec, u8 status)
{
unsigned long flags;
- struct transaction *t = ec->curr;
+ struct transaction *t;
spin_lock_irqsave(&ec->lock, flags);
+ t = ec->curr;
if (!t)
goto unlock;
if (t->wlen > t->wi) {