In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields. Since all the size checking has already happened, use input.pointer (void *) so memcpy() doesn't get confused about how much is being written. Avoids this false-positive warning when run-time memcpy() strict bounds checking is enabled: memcpy: detected field-spanning write (size 4096) of single field (size 36) WARNING: CPU: 0 PID: 357 at drivers/platform/x86/dell/dell-smbios-wmi.c:74 run_smbios_call+0x110/0x1e0 [dell_smbios] Note: is there a missed kfree() in the marked error path? Cc: Hans de Goede <hdegoede@xxxxxxxxxx> Cc: Mark Gross <mgross@xxxxxxxxxxxxxxx> Cc: Mario Limonciello <mario.limonciello@xxxxxxxx> Cc: "Pali Rohár" <pali@xxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: "Uwe Kleine-König" <u.kleine-koenig@xxxxxxxxxxxxxx> Cc: Dell.Client.Kernel@xxxxxxxx Cc: platform-driver-x86@xxxxxxxxxxxxxxx Reported-by: Andy Lavr <andy.lavr@xxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- drivers/platform/x86/dell/dell-smbios-wmi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/platform/x86/dell/dell-smbios-wmi.c b/drivers/platform/x86/dell/dell-smbios-wmi.c index 33f823772733..c410d6d920b8 100644 --- a/drivers/platform/x86/dell/dell-smbios-wmi.c +++ b/drivers/platform/x86/dell/dell-smbios-wmi.c @@ -69,9 +69,10 @@ static int run_smbios_call(struct wmi_device *wdev) if (obj->type == ACPI_TYPE_INTEGER) dev_dbg(&wdev->dev, "SMBIOS call failed: %llu\n", obj->integer.value); + /* output.pointer memory allocation leak? */ return -EIO; } - memcpy(&priv->buf->std, obj->buffer.pointer, obj->buffer.length); + memcpy(input.pointer, obj->buffer.pointer, obj->buffer.length); dev_dbg(&wdev->dev, "result: [%08x,%08x,%08x,%08x]\n", priv->buf->std.output[0], priv->buf->std.output[1], priv->buf->std.output[2], priv->buf->std.output[3]); -- 2.30.2
