Merge tag 'hardening-v6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening fixes from Kees Cook:

 - ARM: stacktrace: include asm/sections.h in asm/stacktrace.h (Arnd
   Bergmann)

 - ubsan: Fix incorrect hand-side used in handle (Junhui Pei)

 - hardening: Require clang 20.1.0 for __counted_by (Nathan Chancellor)

* tag 'hardening-v6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  hardening: Require clang 20.1.0 for __counted_by
  ARM: stacktrace: include asm/sections.h in asm/stacktrace.h
  ubsan: Fix incorrect hand-side used in handle

Author: torvalds

arch/arm/include/asm/stacktrace.h

@@ -2,8 +2,9 @@
 #ifndef __ASM_STACKTRACE_H
 #define __ASM_STACKTRACE_H
 
-#include <asm/ptrace.h>
 #include <linux/llist.h>
+#include <asm/ptrace.h>
+#include <asm/sections.h>
 
 struct stackframe {
 	/*

init/Kconfig

@@ -117,10 +117,11 @@ config CC_HAS_NO_PROFILE_FN_ATTR
 
 config CC_HAS_COUNTED_BY
 	bool
-	# clang needs to be at least 19.1.3 to avoid __bdos miscalculations
-	# https://github.com/llvm/llvm-project/pull/110497
-	# https://github.com/llvm/llvm-project/pull/112636
-	default y if CC_IS_CLANG && CLANG_VERSION >= 190103
+	# clang needs to be at least 20.1.0 to avoid potential crashes
+	# when building structures that contain __counted_by
+	# https://github.com/ClangBuiltLinux/linux/issues/2114
+	# https://github.com/llvm/llvm-project/commit/160fb1121cdf703c3ef5e61fb26c5659eb581489
+	default y if CC_IS_CLANG && CLANG_VERSION >= 200100
 	# supported since gcc 15.1.0
 	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
 	default y if CC_IS_GCC && GCC_VERSION >= 150100

lib/ubsan.c

@@ -333,18 +333,18 @@ EXPORT_SYMBOL(__ubsan_handle_implicit_conversion);
 void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
 {
 	struct overflow_data *data = _data;
-	char rhs_val_str[VALUE_LENGTH];
+	char lhs_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
 	ubsan_prologue(&data->location, "division-overflow");
 
-	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
+	val_to_string(lhs_val_str, sizeof(lhs_val_str), data->type, lhs);
 
 	if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
 		pr_err("division of %s by -1 cannot be represented in type %s\n",
-			rhs_val_str, data->type->type_name);
+			lhs_val_str, data->type->type_name);
 	else
 		pr_err("division by zero\n");