Merge tag 'hardening-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:
 "Beyond some specific LoadPin, UBSAN, and fortify features, there are
  other fixes scattered around in various subsystems where maintainers
  were okay with me carrying them in my tree or were non-responsive but
  the patches were reviewed by others:

   - Replace 0-length and 1-element arrays with flexible arrays in
     various subsystems (Paulo Miguel Almeida, Stephen Rothwell, Kees
     Cook)

   - randstruct: Disable Clang 15 support (Eric Biggers)

   - GCC plugins: Drop -std=gnu++11 flag (Sam James)

   - strpbrk(): Refactor to use strchr() (Andy Shevchenko)

   - LoadPin LSM: Allow root filesystem switching when non-enforcing

   - fortify: Use dynamic object size hints when available

   - ext4: Fix CFI function prototype mismatch

   - Nouveau: Fix DP buffer size arguments

   - hisilicon: Wipe entire crypto DMA pool on error

   - coda: Fully allocate sig_inputArgs

   - UBSAN: Improve arm64 trap code reporting

   - copy_struct_from_user(): Add minimum bounds check on kernel buffer
     size"

* tag 'hardening-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  randstruct: disable Clang 15 support
  uaccess: Add minimum bounds check on kernel buffer size
  arm64: Support Clang UBSAN trap codes for better reporting
  coda: Avoid partial allocation of sig_inputArgs
  gcc-plugins: drop -std=gnu++11 to fix GCC 13 build
  lib/string: Use strchr() in strpbrk()
  crypto: hisilicon: Wipe entire pool on error
  net/i40e: Replace 0-length array with flexible array
  io_uring: Replace 0-length array with flexible array
  ext4: Fix function prototype mismatch for ext4_feat_ktype
  i915/gvt: Replace one-element array with flexible-array member
  drm/nouveau/disp: Fix nvif_outp_acquire_dp() argument size
  LoadPin: Allow filesystem switch when not enforcing
  LoadPin: Move pin reporting cleanly out of locking
  LoadPin: Refactor sysctl initialization
  LoadPin: Refactor read-only check into a helper
  ARM: ixp4xx: Replace 0-length arrays with flexible arrays
  fortify: Use __builtin_dynamic_object_size() when available
  rxrpc: replace zero-lenth array with DECLARE_FLEX_ARRAY() helper

2 files changed, 24 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/brk-imm.h b/arch/arm64/include/asm/brk-imm.h
index 6e000113e508..1abdcd508a11 100644
--- a/arch/arm64/include/asm/brk-imm.h
+++ b/arch/arm64/include/asm/brk-imm.h
@@ -17,6 +17,7 @@
  * 0x401: for compile time BRK instruction
  * 0x800: kernel-mode BUG() and WARN() traps
  * 0x9xx: tag-based KASAN trap (allowed values 0x900 - 0x9ff)
+ * 0x55xx: Undefined Behavior Sanitizer traps ('U' << 8)
  * 0x8xxx: Control-Flow Integrity traps
  */
 #define KPROBES_BRK_IMM			0x004
@@ -28,6 +29,8 @@
 #define BUG_BRK_IMM			0x800
 #define KASAN_BRK_IMM			0x900
 #define KASAN_BRK_MASK			0x0ff
+#define UBSAN_BRK_IMM			0x5500
+#define UBSAN_BRK_MASK			0x00ff
 
 #define CFI_BRK_IMM_TARGET		GENMASK(4, 0)
 #define CFI_BRK_IMM_TYPE		GENMASK(9, 5)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 4c0caa589e12..87f42eb1c950 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -26,6 +26,7 @@
 #include <linux/syscalls.h>
 #include <linux/mm_types.h>
 #include <linux/kasan.h>
+#include <linux/ubsan.h>
 #include <linux/cfi.h>
 
 #include <asm/atomic.h>
@@ -1074,6 +1075,19 @@ static struct break_hook kasan_break_hook = {
 };
 #endif
 
+#ifdef CONFIG_UBSAN_TRAP
+static int ubsan_handler(struct pt_regs *regs, unsigned long esr)
+{
+	die(report_ubsan_failure(regs, esr & UBSAN_BRK_MASK), regs, esr);
+	return DBG_HOOK_HANDLED;
+}
+
+static struct break_hook ubsan_break_hook = {
+	.fn	= ubsan_handler,
+	.imm	= UBSAN_BRK_IMM,
+	.mask	= UBSAN_BRK_MASK,
+};
+#endif
 
 #define esr_comment(esr) ((esr) & ESR_ELx_BRK64_ISS_COMMENT_MASK)
 
@@ -1092,6 +1106,10 @@ int __init early_brk64(unsigned long addr, unsigned long esr,
 	if ((esr_comment(esr) & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)
 		return kasan_handler(regs, esr) != DBG_HOOK_HANDLED;
 #endif
+#ifdef CONFIG_UBSAN_TRAP
+	if ((esr_comment(esr) & ~UBSAN_BRK_MASK) == UBSAN_BRK_IMM)
+		return ubsan_handler(regs, esr) != DBG_HOOK_HANDLED;
+#endif
 	return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
 }
 
@@ -1105,5 +1123,8 @@ void __init trap_init(void)
 #ifdef CONFIG_KASAN_SW_TAGS
 	register_kernel_break_hook(&kasan_break_hook);
 #endif
+#ifdef CONFIG_UBSAN_TRAP
+	register_kernel_break_hook(&ubsan_break_hook);
+#endif
 	debug_traps_init();
 }