2012/11/6 Ming Lei <tom.leiming@xxxxxxxxx>: > On Tue, Nov 6, 2012 at 1:18 AM, Takashi Iwai <tiwai@xxxxxxx> 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 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ 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 <jlee@xxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
