firmware: add call to LSM hook before firmware sysfs fallback

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>
Signed-off-by: James Morris <james.morris@microsoft.com>

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 7f73274..2023242 100644 (file)
--- 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);
 }