kmsan: core: kmsan_in_runtime() should return true in NMI context

Without that, every call to __msan_poison_alloca() in NMI may end up allocating memory, which is NMI-unsafe. Link: https://lkml.kernel.org/r/[email protected] Link: https://lore.kernel.org/lkml/[email protected]/ Signed-off-by: Alexander Potapenko <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Kees Cook <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
torvalds · Nov 8, 2022 · cbadaf7 · cbadaf7
1 parent db5e8d8
commit cbadaf7
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/mm/kmsan/kmsan.h b/mm/kmsan/kmsan.h
@@ -124,6 +124,8 @@ static __always_inline bool kmsan_in_runtime(void)
 {
  if ((hardirq_count() >> HARDIRQ_SHIFT) > 1)
  return true;
+ if (in_nmi())
+ return true;
  return kmsan_get_context()->kmsan_in_runtime;
 }