Merge tag 'bounds-fixes-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull bounds fixes from Kees Cook:
 "These are a handful of buffer and array bounds fixes that I've been
  carrying in preparation for the coming memcpy improvements and the
  enabling of '-Warray-bounds' globally.

  There are additional similar fixes in other maintainer's trees, but
  these ended up getting carried by me. :)"

* tag 'bounds-fixes-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  media: omap3isp: Use struct_group() for memcpy() region
  tpm: vtpm_proxy: Check length to avoid compiler warning
  alpha: Silence -Warray-bounds warnings
  m68k: cmpxchg: Dereference matching size
  intel_th: msu: Use memset_startat() for clearing hw header
  KVM: x86: Replace memset() "optimization" with normal per-field writes

4 files changed, 15 insertions, 15 deletions

diff --git a/arch/alpha/mm/init.c b/arch/alpha/mm/init.c
index f6114d03357c..7511723b7669 100644
--- a/arch/alpha/mm/init.c
+++ b/arch/alpha/mm/init.c
@@ -76,14 +76,14 @@ pgd_alloc(struct mm_struct *mm)
 pmd_t *
 __bad_pagetable(void)
 {
-	memset((void *) EMPTY_PGT, 0, PAGE_SIZE);
+	memset(absolute_pointer(EMPTY_PGT), 0, PAGE_SIZE);
 	return (pmd_t *) EMPTY_PGT;
 }
 
 pte_t
 __bad_page(void)
 {
-	memset((void *) EMPTY_PGE, 0, PAGE_SIZE);
+	memset(absolute_pointer(EMPTY_PGE), 0, PAGE_SIZE);
 	return pte_mkdirty(mk_pte(virt_to_page(EMPTY_PGE), PAGE_SHARED));
 }
 
@@ -253,7 +253,7 @@ void __init paging_init(void)
 	free_area_init(max_zone_pfn);
 
 	/* Initialize the kernel's ZERO_PGE. */
-	memset((void *)ZERO_PGE, 0, PAGE_SIZE);
+	memset(absolute_pointer(ZERO_PGE), 0, PAGE_SIZE);
 }
 
 #if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)
diff --git a/arch/m68k/include/asm/cmpxchg.h b/arch/m68k/include/asm/cmpxchg.h
index e8ca4b0ccefa..6cf464cdab06 100644
--- a/arch/m68k/include/asm/cmpxchg.h
+++ b/arch/m68k/include/asm/cmpxchg.h
@@ -4,8 +4,7 @@
 
 #include <linux/irqflags.h>
 
-struct __xchg_dummy { unsigned long a[100]; };
-#define __xg(x) ((volatile struct __xchg_dummy *)(x))
+#define __xg(type, x) ((volatile type *)(x))
 
 extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
 
@@ -50,7 +49,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 			 "1:\n\t"
 			 "casb %0,%1,%2\n\t"
 			 "jne 1b"
-			 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
+			 : "=&d" (x) : "d" (x), "m" (*__xg(u8, ptr)) : "memory");
 		break;
 	case 2:
 		__asm__ __volatile__
@@ -58,7 +57,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 			 "1:\n\t"
 			 "casw %0,%1,%2\n\t"
 			 "jne 1b"
-			 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
+			 : "=&d" (x) : "d" (x), "m" (*__xg(u16, ptr)) : "memory");
 		break;
 	case 4:
 		__asm__ __volatile__
@@ -66,7 +65,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 			 "1:\n\t"
 			 "casl %0,%1,%2\n\t"
 			 "jne 1b"
-			 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
+			 : "=&d" (x) : "d" (x), "m" (*__xg(u32, ptr)) : "memory");
 		break;
 	default:
 		x = __invalid_xchg_size(x, ptr, size);
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e86d610dc6b7..d8c087f1b831 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5395,8 +5395,13 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop)
 
 void init_decode_cache(struct x86_emulate_ctxt *ctxt)
 {
-	memset(&ctxt->rip_relative, 0,
-	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
+	/* Clear fields that are set conditionally but read without a guard. */
+	ctxt->rip_relative = false;
+	ctxt->rex_prefix = 0;
+	ctxt->lock_prefix = 0;
+	ctxt->rep_prefix = 0;
+	ctxt->regs_valid = 0;
+	ctxt->regs_dirty = 0;
 
 	ctxt->io_read.pos = 0;
 	ctxt->io_read.end = 0;
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 39eded2426ff..840ddb4a9302 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -336,11 +336,7 @@ struct x86_emulate_ctxt {
 		fastop_t fop;
 	};
 	int (*check_perm)(struct x86_emulate_ctxt *ctxt);
-	/*
-	 * The following six fields are cleared together,
-	 * the rest are initialized unconditionally in x86_decode_insn
-	 * or elsewhere
-	 */
+
 	bool rip_relative;
 	u8 rex_prefix;
 	u8 lock_prefix;