2012/11/6 Ming Lei <tom.leim...@gmail.com>:
> On Tue, Nov 6, 2012 at 1:18 AM, Takashi Iwai <ti...@suse.de> wrote:
>>
>> To be noted, it doesn't support the firmwares via udev but only the
>> direct loading, and the check for built-in firmware is missing, too.
>
> Generally, both direct loading and udev may request one same firmware
> image. And after check failed, current firmware load will fallback on udev
> to complete loading, so looks a check-failed firmware still can be loaded
> into kernel no matter if there is firmware signature check or not.
>
>
> Thanks,
> --
> Ming Lei
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The udev direct write firmware through data attribute, maybe we can do
the same signature verification in firmware_data_write? The following
patch didn't test yet.
Thanks
Joey Lee
>From 035dde5fadc9e7f4b7811b18d3a5094ef88e8bbb Mon Sep 17 00:00:00 2001
From: Lee, Chun-Yi <j...@suse.com>
Date: Tue, 6 Nov 2012 13:07:04 +0800
Subject: [PATCH] firmware: Add signature check to firmware_data_write
---
drivers/base/firmware_class.c | 18 ++++++++++++++++++
1 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 8945f4e..40d8cc6 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -621,6 +621,7 @@ static ssize_t firmware_data_write(struct file
*filp, struct kobject *kobj,
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware_buf *buf;
ssize_t retval;
+ bool success = false;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
@@ -655,6 +656,23 @@ static ssize_t firmware_data_write(struct file
*filp, struct kobject *kobj,
}
buf->size = max_t(size_t, offset, buf->size);
+
+#ifdef CONFIG_FIRMWARE_SIG
+ for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
+ snprintf(path, PATH_MAX, "%s/%s.sig", fw_path[i], buf->fw_id);
+ if (verify_signature(buf, path))
+ success = true;
+ }
+ if (!success) {
+ pr_err("Invalid signature file %s\n", path);
+ if (sig_enforce) {
+ vfree(buf->data);
+ buf->data = NULL;
+ buf->size = 0;
+ }
+ retval = -ENOENT;
+ }
+#endif /* CONFIG_FIRMWARE_SIG */
out:
mutex_unlock(&fw_lock);
return retval;
--
1.6.4.2
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