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Message-Id: <20180508030811.12256-1-baijiaju1990@gmail.com>
Date: Tue, 8 May 2018 11:08:11 +0800
From: Jia-Ju Bai <baijiaju1990@...il.com>
To: rjw@...ysocki.net, lenb@...nel.org
Cc: linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
Jia-Ju Bai <baijiaju1990@...il.com>
Subject: [PATCH] acpi: scan: Fix a possible data race in acpi_scan_hotplug_enabled
The write operation to "hotplug->enabled" is protected by
the lock on line 1760, but the read operation to
this data on line 1755 is not protected by the lock.
Thus, there may exist a data race for "hotplug->enabled".
To fix this data race, the read operation to "hotplug->enabled" is
also protected by the lock.
Signed-off-by: Jia-Ju Bai <baijiaju1990@...il.com>
---
drivers/acpi/scan.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 970dd87d347c..e21d7b0f7179 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1752,11 +1752,13 @@ static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
{
- if (!!hotplug->enabled == !!val)
- return;
-
mutex_lock(&acpi_scan_lock);
+ if (!!hotplug->enabled == !!val) {
+ mutex_unlock(&acpi_scan_lock);
+ return;
+ }
+
hotplug->enabled = val;
mutex_unlock(&acpi_scan_lock);
--
2.17.0
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