diff mbox

[v6,4/8] firmware: add call to LSM hook before firmware sysfs fallback

Message ID 1531505163-20227-5-git-send-email-zohar@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mimi Zohar July 13, 2018, 6:05 p.m. UTC 
Add an LSM hook prior to allowing firmware sysfs fallback loading.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>

---
Changelog v4:
- call new LSM security_kernel_load_data hook

Changelog v2:
- call security_kernel_read_blob()
- rename the READING_FIRMWARE_FALLBACK kernel_read_file_id enumeration to
READING_FIRMWARE_FALLBACK_SYSFS.

 drivers/base/firmware_loader/fallback.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Kees Cook July 15, 2018, 2:24 a.m. UTC | #1 
On Fri, Jul 13, 2018 at 11:05 AM, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> Add an LSM hook prior to allowing firmware sysfs fallback loading.
>
> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees
diff mbox

Patch

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 7f732744f0d3..202324291542 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -651,6 +651,8 @@  static bool fw_force_sysfs_fallback(enum fw_opt opt_flags)
 
 static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 {
+	int ret;
+
 	if (fw_fallback_config.ignore_sysfs_fallback) {
 		pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n");
 		return false;
@@ -659,6 +661,11 @@  static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 	if ((opt_flags & FW_OPT_NOFALLBACK))
 		return false;
 
+	/* Also permit LSMs and IMA to fail firmware sysfs fallback */
+	ret = security_kernel_load_data(LOADING_FIRMWARE);
+	if (ret < 0)
+		return ret;
+
 	return fw_force_sysfs_fallback(opt_flags);
 }