[PATCH 3.4 015/177] firmware_class: make sure fw requests contain a name

[lizf]

From: Kees Cook <keescook@xxxxxxxxxxxx>

3.4.106-rc1 review patch.  If anyone has any objections, please let me know.

------------------


commit 471b095dfe0d693a8d624cbc716d1ee4d74eb437 upstream.

An empty firmware request name will trigger warnings when building
device names. Make sure this is caught earlier and rejected.

The warning was visible via the test_firmware.ko module interface:

echo -ne "\x00" > /sys/devices/virtual/misc/test_firmware/trigger_request

Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Tested-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@xxxxxxxxxx>
---
 drivers/base/firmware_class.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 5401814..b7a4fe5 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -588,6 +588,9 @@ request_firmware(const struct firmware **firmware_p, const char *name,
 	struct firmware_priv *fw_priv;
 	int ret;
 
+	if (!name || name[0] == '\0')
+		return -EINVAL;
+
 	fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
 					    false);
 	if (IS_ERR_OR_NULL(fw_priv))
-- 
1.9.1

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