Re: [PATCH v2] acpi: Fix use-after-free in acpi_ipmi.c
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2020-11-26 14:22:43
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On Thu, Nov 26, 2020 at 2:26 AM Youling Tang [off-list ref] wrote:
quoted hunk ↗ jump to hunk
kfree() has been called inside put_device so anther kfree would cause a use-after-free bug. Signed-off-by: Youling Tang <redacted> --- drivers/acpi/acpi_ipmi.c | 1 - 1 file changed, 1 deletion(-)diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c index 9d6c0fc..18edf8b 100644 --- a/drivers/acpi/acpi_ipmi.c +++ b/drivers/acpi/acpi_ipmi.c@@ -142,7 +142,6 @@ static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device) { ipmi_destroy_user(ipmi_device->user_interface); put_device(ipmi_device->dev);
Does putting ipmi_device->dev (which is a different object than ipmi_device itself) really cause ipmi_device to be freed automatically? If not, the change below will introduce a memory leak.
- kfree(ipmi_device); } static void ipmi_dev_release_kref(struct kref *kref) --