From: Dan Williams <dan.j.williams@intel.com>
To: rafael.j.wysocki@intel.com
Cc: Anush Seetharaman <anush.seetharaman@intel.com>,
Tiffany Kasanicky <tiffany.j.kasanicky@intel.com>,
Ryon Jensen <ryon.jensen@intel.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
linux-acpi@vger.kernel.org,
Kristin Jacque <kristin.jacque@intel.com>,
Zhang Rui <rui.zhang@intel.com>
Subject: [PATCH] acpi: fix acpi_get_table() leak / acpi-sysfs denial of service
Date: Tue, 25 Apr 2017 12:39:20 -0700 [thread overview]
Message-ID: <149314916034.8899.7439820192725219189.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
Reading an ACPI table through the /sys/firmware/acpi/tables interface
more than 65,536 times leads to the following log message:
ACPI Error: Table ffff88033595eaa8, Validation count is zero after increment
(20170119/tbutils-423)
...and the table being unavailable until the next reboot. Add the
missing acpi_put_table() so the table ->validation_count is decremented
after each read.
Cc: <stable@vger.kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: Kristin Jacque <kristin.jacque@intel.com>
Cc: Tiffany Kasanicky <tiffany.j.kasanicky@intel.com>
Cc: Ryon Jensen <ryon.jensen@intel.com>
Reported-by: Anush Seetharaman <anush.seetharaman@intel.com>
Fixes: 1c8fce27e275 ("ACPI: introduce drivers/acpi/sysfs.c")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/acpi/sysfs.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c
index cf05ae973381..531ddabf0390 100644
--- a/drivers/acpi/sysfs.c
+++ b/drivers/acpi/sysfs.c
@@ -333,14 +333,17 @@ static ssize_t acpi_table_show(struct file *filp, struct kobject *kobj,
container_of(bin_attr, struct acpi_table_attr, attr);
struct acpi_table_header *table_header = NULL;
acpi_status status;
+ ssize_t rc;
status = acpi_get_table(table_attr->name, table_attr->instance,
&table_header);
if (ACPI_FAILURE(status))
return -ENODEV;
- return memory_read_from_buffer(buf, count, &offset,
- table_header, table_header->length);
+ rc = memory_read_from_buffer(buf, count, &offset, table_header,
+ table_header->length);
+ acpi_put_table(table);
+ return rc;
}
static int acpi_table_attr_init(struct kobject *tables_obj,
next reply other threads:[~2017-04-25 19:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-25 19:39 Dan Williams [this message]
2017-04-26 1:37 ` [PATCH] acpi: fix acpi_get_table() leak / acpi-sysfs denial of service Zheng, Lv
2017-04-26 19:19 ` kbuild test robot
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