From: Mark Langsdorf mlangsdo@redhat.com
commit e483bb9a991bdae29a0caa4b3a6d002c968f94aa upstream.
In cm_write(), buf is always freed when reaching the end of the function. If the requested count is less than table.length, the allocated buffer will be freed but subsequent calls to cm_write() will still try to access it.
Remove the unconditional kfree(buf) at the end of the function and set the buf to NULL in the -EINVAL error path to match the rest of function.
Fixes: 03d1571d9513 ("ACPI: custom_method: fix memory leaks") 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 --- drivers/acpi/custom_method.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -57,6 +57,7 @@ static ssize_t cm_write(struct file *fil (*ppos + count < count) || (count > uncopied_bytes)) { kfree(buf); + buf = NULL; return -EINVAL; }
@@ -78,7 +79,6 @@ static ssize_t cm_write(struct file *fil add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE); }
- kfree(buf); return count; }