Merge tag 'meminit-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull structleak fix from Kees Cook:
 "Disable gcc-based stack variable auto-init under KASAN (Arnd
  Bergmann).

  This fixes a bunch of build warnings under KASAN and the
  gcc-plugin-based stack auto-initialization features (which are
  arguably redundant, so better to let KASAN control this)"

* tag 'meminit-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  structleak: disable STRUCTLEAK_BYREF in combination with KASAN_STACK

1 files changed, 7 insertions, 0 deletions

diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index a1ffe2eb4d5f..af4c979b38ee 100644
--- a/security/Kconfig.hardening
+++ b/security/Kconfig.hardening
@@ -61,6 +61,7 @@ choice
         config GCC_PLUGIN_STRUCTLEAK_BYREF
                 bool "zero-init structs passed by reference (strong)"
                 depends on GCC_PLUGINS
+                depends on !(KASAN && KASAN_STACK=1)
                 select GCC_PLUGIN_STRUCTLEAK
                 help
                   Zero-initialize any structures on the stack that may
@@ -70,9 +71,15 @@ choice
                   exposures, like CVE-2017-1000410:
                   https://git.kernel.org/linus/06e7e776ca4d3654
 
+                  As a side-effect, this keeps a lot of variables on the
+                  stack that can otherwise be optimized out, so combining
+                  this with CONFIG_KASAN_STACK can lead to a stack overflow
+                  and is disallowed.
+
         config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
                 bool "zero-init anything passed by reference (very strong)"
                 depends on GCC_PLUGINS
+                depends on !(KASAN && KASAN_STACK=1)
                 select GCC_PLUGIN_STRUCTLEAK
                 help
                   Zero-initialize any stack variables that may be passed