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| author | Dan Williams <dan.j.williams@intel.com> | 2017-04-25 21:58:31 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-04-27 00:27:49 +0200 |
| commit | 0de0e198bc7191a0e46cf71f66fec4d07ca91396 (patch) | |
| tree | c87c76de72cb5ba4f4d93a3b85f4f39ed5b92eaf /drivers/acpi | |
| parent | Linux 4.11-rc8 (diff) | |
| download | linux-0de0e198bc7191a0e46cf71f66fec4d07ca91396.tar.xz linux-0de0e198bc7191a0e46cf71f66fec4d07ca91396.zip | |
ACPI / sysfs: fix acpi_get_table() leak / acpi-sysfs denial of service
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.
Reported-by: Anush Seetharaman <anush.seetharaman@intel.com>
Fixes: 174cc7187e6f "ACPICA: Tables: Back port acpi_get_table_with_size() ..."
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/sysfs.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c index cf05ae973381..5180fef9eb49 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_header); + return rc; } static int acpi_table_attr_init(struct kobject *tables_obj, |