1 files changed, 47 insertions, 11 deletions

diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index d9fd9988ef27..74271dba4f94 100644
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -67,23 +67,59 @@ config GCC_PLUGIN_LATENT_ENTROPY
            * https://pax.grsecurity.net/
 
 config GCC_PLUGIN_STRUCTLEAK
-        bool "Force initialization of variables containing userspace addresses"
+        bool "Zero initialize stack variables"
         help
-          This plugin zero-initializes any structures containing a
-          __user attribute. This can prevent some classes of information
-          exposures.
-
-          This plugin was ported from grsecurity/PaX. More information at:
+          While the kernel is built with warnings enabled for any missed
+          stack variable initializations, this warning is silenced for
+          anything passed by reference to another function, under the
+          occasionally misguided assumption that the function will do
+          the initialization. As this regularly leads to exploitable
+          flaws, this plugin is available to identify and zero-initialize
+          such variables, depending on the chosen level of coverage.
+
+          This plugin was originally ported from grsecurity/PaX. More
+          information at:
            * https://grsecurity.net/
            * https://pax.grsecurity.net/
 
-config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
-        bool "Force initialize all struct type variables passed by reference"
+choice
+        prompt "Coverage"
         depends on GCC_PLUGIN_STRUCTLEAK
-        depends on !COMPILE_TEST
+        default GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
         help
-          Zero initialize any struct type local variable that may be passed by
-          reference without having been initialized.
+          This chooses the level of coverage over classes of potentially
+          uninitialized variables. The selected class will be
+          zero-initialized before use.
+
+        config GCC_PLUGIN_STRUCTLEAK_USER
+                bool "structs marked for userspace"
+                help
+                  Zero-initialize any structures on the stack containing
+                  a __user attribute. This can prevent some classes of
+                  uninitialized stack variable exploits and information
+                  exposures, like CVE-2013-2141:
+                  https://git.kernel.org/linus/b9e146d8eb3b9eca
+
+        config GCC_PLUGIN_STRUCTLEAK_BYREF
+                bool "structs passed by reference"
+                help
+                  Zero-initialize any structures on the stack that may
+                  be passed by reference and had not already been
+                  explicitly initialized. This can prevent most classes
+                  of uninitialized stack variable exploits and information
+                  exposures, like CVE-2017-1000410:
+                  https://git.kernel.org/linus/06e7e776ca4d3654
+
+        config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
+                bool "anything passed by reference"
+                help
+                  Zero-initialize any stack variables that may be passed
+                  by reference and had not already been explicitly
+                  initialized. This is intended to eliminate all classes
+                  of uninitialized stack variable exploits and information
+                  exposures.
+
+endchoice
 
 config GCC_PLUGIN_STRUCTLEAK_VERBOSE
         bool "Report forcefully initialized variables"