diff --git a/Makefile b/Makefile
index ffd7a912fc46..5041e908f051 100644
--- a/Makefile
+++ b/Makefile
@@ -478,7 +478,7 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
-export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_KMSAN
 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
@@ -898,6 +898,7 @@ KBUILD_CFLAGS += $(call cc-option,-fcf-protection=none)
 endif
 
 include scripts/Makefile.kasan
+include scripts/Makefile.kmsan
 include scripts/Makefile.extrawarn
 include scripts/Makefile.ubsan
 
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index c8181392f70d..dd4bd8c5d97a 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -12,6 +12,7 @@
 #undef CONFIG_PARAVIRT_XXL
 #undef CONFIG_PARAVIRT_SPINLOCKS
 #undef CONFIG_KASAN
+#undef CONFIG_KMSAN
 
 /* cpu_feature_enabled() cannot be used this early */
 #define USE_EARLY_PGTABLE_L5
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index b7c3ea4cb19d..1218672bad85 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -35,6 +35,7 @@
 #include <asm/asm.h>
 #include <asm/smap.h>
 #include <asm/pgtable_types.h>
+#include <asm/kmsan.h>
 #include <asm/export.h>
 #include <asm/frame.h>
 #include <asm/nospec-branch.h>
@@ -168,12 +169,14 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 	PUSH_AND_CLEAR_REGS rax=$-ENOSYS
 
 	TRACE_IRQS_OFF
+	KMSAN_SYSCALL_ENTER
 
 	/* IRQs are off. */
 	movq	%rax, %rdi
 	movq	%rsp, %rsi
 	call	do_syscall_64		/* returns with IRQs disabled */
 
+	KMSAN_SYSCALL_EXIT
 	TRACE_IRQS_IRETQ		/* we're about to change IF */
 
 	/*
@@ -575,6 +578,7 @@ ENTRY(interrupt_entry)
 
 1:
 	ENTER_IRQ_STACK old_rsp=%rdi save_ret=1
+	KMSAN_INTERRUPT_ENTER
 	/* We entered an interrupt context - irqs are off: */
 	TRACE_IRQS_OFF
 
@@ -604,12 +608,14 @@ common_interrupt:
 	addq	$-0x80, (%rsp)			/* Adjust vector to [-256, -1] range */
 	call	interrupt_entry
 	UNWIND_HINT_REGS indirect=1
+	KMSAN_UNPOISON_PT_REGS
 	call	do_IRQ	/* rdi points to pt_regs */
 	/* 0(%rsp): old RSP */
 ret_from_intr:
 	DISABLE_INTERRUPTS(CLBR_ANY)
 	TRACE_IRQS_OFF
 
+	KMSAN_INTERRUPT_EXIT
 	LEAVE_IRQ_STACK
 
 	testb	$3, CS(%rsp)
@@ -802,6 +808,7 @@ ENTRY(\sym)
 .Lcommon_\sym:
 	call	interrupt_entry
 	UNWIND_HINT_REGS indirect=1
+	KMSAN_UNPOISON_PT_REGS
 	call	\do_sym	/* rdi points to pt_regs */
 	jmp	ret_from_intr
 END(\sym)
@@ -909,15 +916,18 @@ apicinterrupt IRQ_WORK_VECTOR			irq_work_interrupt		smp_irq_work_interrupt
 
 	.if \shift_ist != -1
 	subq	$\ist_offset, CPU_TSS_IST(\shift_ist)
+	KMSAN_IST_ENTER(\shift_ist)
 	.endif
 
 	.if \read_cr2
 	movq	%r12, %rdx			/* Move CR2 into 3rd argument */
 	.endif
 
+	KMSAN_UNPOISON_PT_REGS
 	call	\do_sym
 
 	.if \shift_ist != -1
+	KMSAN_IST_EXIT(\shift_ist)
 	addq	$\ist_offset, CPU_TSS_IST(\shift_ist)
 	.endif
 
@@ -1079,7 +1089,9 @@ ENTRY(do_softirq_own_stack)
 	pushq	%rbp
 	mov	%rsp, %rbp
 	ENTER_IRQ_STACK regs=0 old_rsp=%r11
+	KMSAN_SOFTIRQ_ENTER
 	call	__do_softirq
+	KMSAN_SOFTIRQ_EXIT
 	LEAVE_IRQ_STACK regs=0
 	leaveq
 	ret
@@ -1466,9 +1478,12 @@ ENTRY(nmi)
 	 * done with the NMI stack.
 	 */
 
+	KMSAN_NMI_ENTER
 	movq	%rsp, %rdi
 	movq	$-1, %rsi
+	KMSAN_UNPOISON_PT_REGS
 	call	do_nmi
+	KMSAN_NMI_EXIT
 
 	/*
 	 * Return back to user mode.  We must *not* do the normal exit
@@ -1678,10 +1693,13 @@ end_repeat_nmi:
 	call	paranoid_entry
 	UNWIND_HINT_REGS
 
+	KMSAN_NMI_ENTER
 	/* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
 	movq	%rsp, %rdi
 	movq	$-1, %rsi
+	KMSAN_UNPOISON_PT_REGS
 	call	do_nmi
+	KMSAN_NMI_EXIT
 
 	/* Always restore stashed CR3 value (see paranoid_entry) */
 	RESTORE_CR3 scratch_reg=%r15 save_reg=%r14
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 288b065955b7..ea9fbf09f43b 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -7,18 +7,20 @@
 #endif
 
 #ifdef CONFIG_KASAN
-#define KASAN_STACK_ORDER 1
+#define EXTRA_STACK_ORDER 1
+#elif defined(CONFIG_KMSAN)
+#define EXTRA_STACK_ORDER 2
 #else
-#define KASAN_STACK_ORDER 0
+#define EXTRA_STACK_ORDER 0
 #endif
 
-#define THREAD_SIZE_ORDER	(2 + KASAN_STACK_ORDER)
+#define THREAD_SIZE_ORDER	(2 + EXTRA_STACK_ORDER)
 #define THREAD_SIZE  (PAGE_SIZE << THREAD_SIZE_ORDER)
 
-#define EXCEPTION_STACK_ORDER (0 + KASAN_STACK_ORDER)
+#define EXCEPTION_STACK_ORDER (0 + EXTRA_STACK_ORDER)
 #define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
 
-#define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
+#define IRQ_STACK_ORDER (2 + EXTRA_STACK_ORDER)
 #define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)
 
 /*
diff --git a/block/blk.h b/block/blk.h
index 47fba9362e60..9ee271a22423 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -78,6 +78,13 @@ static inline bool biovec_phys_mergeable(struct request_queue *q,
 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
 
+#ifdef CONFIG_KMSAN
+	/*
+	 * Merging consequent physical pages may not work correctly under KMSAN
+	 * if their metadata pages aren't consequent. Just disable merging.
+	 */
+	return false;
+#endif
 	if (addr1 + vec1->bv_len != addr2)
 		return false;
 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 2222fa795284..c87c5416a802 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -216,6 +216,15 @@ struct page {
 					   not kmapped, ie. highmem) */
 #endif /* WANT_PAGE_VIRTUAL */
 
+#ifdef CONFIG_KMSAN
+	/*
+	 * Bits in struct page are scarce, so the LSB in *shadow is used to
+	 * indicate whether the page should be ignored by KMSAN or not.
+	 */
+	struct page *shadow;
+	struct page *origin;
+#endif
+
 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
 	int _last_cpupid;
 #endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 7417e0207b48..e0f6e95c22ed 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -15,6 +15,7 @@
 #include <linux/sem.h>
 #include <linux/shm.h>
 #include <linux/kcov.h>
+#include <linux/kmsan.h>
 #include <linux/mutex.h>
 #include <linux/plist.h>
 #include <linux/hrtimer.h>
@@ -1172,6 +1173,10 @@ struct task_struct {
 	unsigned int			kasan_depth;
 #endif
 
+#ifdef CONFIG_KMSAN
+	struct kmsan_task_state		kmsan;
+#endif
+
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	/* Index of current stored address in ret_stack: */
 	int				curr_ret_stack;
diff --git a/init/main.c b/init/main.c
index 91f6ebb30ef0..afcca2a38348 100644
--- a/init/main.c
+++ b/init/main.c
@@ -32,6 +32,7 @@
 #include <linux/nmi.h>
 #include <linux/percpu.h>
 #include <linux/kmod.h>
+#include <linux/kmsan.h>
 #include <linux/vmalloc.h>
 #include <linux/kernel_stat.h>
 #include <linux/start_kernel.h>
@@ -554,6 +555,7 @@ static void __init mm_init(void)
 	 */
 	page_ext_init_flatmem();
 	report_meminit();
+	kmsan_initialize_shadow();
 	mem_init();
 	kmem_cache_init();
 	kmemleak_init();
@@ -625,6 +627,7 @@ asmlinkage __visible void __init start_kernel(void)
 	sort_main_extable();
 	trap_init();
 	mm_init();
+	kmsan_initialize();
 
 	ftrace_init();
 
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 460efd3ef742..529a86eb1dd1 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -233,8 +233,8 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle,
 	if (parts.slabindex > depot_index) {
 		WARN(1, "slab index %d out of bounds (%d) for stack id %08x\n",
 			parts.slabindex, depot_index, handle);
-		__memset(trace, 0, sizeof(*trace));
-		return;
+		*entries = NULL;
+		return 0;
 	}
 	slab = stack_slabs[parts.slabindex];
 	stack = slab + offset;
@@ -299,7 +299,8 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
 		 * contexts and I/O.
 		 */
 		alloc_flags &= ~GFP_ZONEMASK;
-		alloc_flags &= (GFP_ATOMIC | GFP_KERNEL);
+		alloc_flags &= (GFP_ATOMIC | GFP_KERNEL |
+				__GFP_NO_KMSAN_SHADOW);
 		alloc_flags |= __GFP_NOWARN;
 		page = alloc_pages(alloc_flags, STACK_ALLOC_ORDER);
 		if (page)
diff --git a/mm/Makefile b/mm/Makefile
index d996846697ef..419e6e02dfaf 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_PAGE_POISONING) += page_poison.o
 obj-$(CONFIG_SLAB) += slab.o
 obj-$(CONFIG_SLUB) += slub.o
 obj-$(CONFIG_KASAN)	+= kasan/
+obj-$(CONFIG_KMSAN)	+= kmsan/
 obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_MEMTEST)		+= memtest.o
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 179d55af5852..f9f38f7c1cd4 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -140,6 +140,12 @@ _c_flags += $(if $(patsubst n%,, \
 		$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
 endif
 
+ifeq ($(CONFIG_KMSAN),y)
+_c_flags += $(if $(patsubst n%,, \
+		$(KMSAN_SANITIZE_$(basetarget).o)$(KMSAN_SANITIZE)y), \
+		$(CFLAGS_KMSAN))
+endif
+
 ifeq ($(CONFIG_UBSAN),y)
 _c_flags += $(if $(patsubst n%,, \
 		$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
