diff options
| author | Mark Langsdorf <mlangsdo@redhat.com> | 2021-04-27 13:54:33 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-11 14:04:01 +0200 |
| commit | 6a4f786f8eb5afdb5cdbdfe418a00ac6340f2120 (patch) | |
| tree | b796b13d6025fab308fa6e4ce6a73765a34f57e0 /drivers/acpi | |
| parent | 72814a94c38a33239793f7622cec6ace1e540c4b (diff) | |
ACPI: custom_method: fix a possible memory leak
commit 1cfd8956437f842836e8a066b40d1ec2fc01f13e upstream.
In cm_write(), if the 'buf' is allocated memory but not fully consumed,
it is possible to reallocate the buffer without freeing it by passing
'*ppos' as 0 on a subsequent call.
Add an explicit kfree() before kzalloc() to prevent the possible memory
leak.
Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Mark Langsdorf <mlangsdo@redhat.com>
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/custom_method.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c index dfe097d07202..e7716c7b9be7 100644 --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -44,6 +44,8 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf, sizeof(struct acpi_table_header))) return -EFAULT; uncopied_bytes = max_size = table.length; + /* make sure the buf is not allocated */ + kfree(buf); buf = kzalloc(max_size, GFP_KERNEL); if (!buf) return -ENOMEM; |