diff --git a/libunwind/src/AddressSpace.hpp b/libunwind/src/AddressSpace.hpp
index 5551c7d4bef1c..8a337dac9f4f5 100644
--- a/libunwind/src/AddressSpace.hpp
+++ b/libunwind/src/AddressSpace.hpp
@@ -621,6 +621,9 @@ inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr,
   }
   // Try to find the unwind info using `dl_find_object`
   dl_find_object findResult;
+#if __has_feature(memory_sanitizer)
+  __builtin_memset(&findResult, 0, sizeof(dl_find_object));
+#endif
   if (dlFindObject && dlFindObject((void *)targetAddr, &findResult) == 0) {
     if (findResult.dlfo_eh_frame == nullptr) {
       // Found an entry for `targetAddr`, but there is no unwind info.
diff --git a/libunwind/src/UnwindLevel1-gcc-ext.c b/libunwind/src/UnwindLevel1-gcc-ext.c
index 32c872ffade1f..c906ce263965c 100644
--- a/libunwind/src/UnwindLevel1-gcc-ext.c
+++ b/libunwind/src/UnwindLevel1-gcc-ext.c
@@ -133,6 +133,10 @@ _LIBUNWIND_EXPORT _Unwind_Reason_Code
 _Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
   unw_cursor_t cursor;
   unw_context_t uc;
+#if __has_feature(memory_sanitizer)
+  __builtin_memset(&cursor, 0, sizeof(cursor));
+  __builtin_memset(&uc, 0, sizeof(uc));
+#endif
   __unw_getcontext(&uc);
   __unw_init_local(&cursor, &uc);
 
diff --git a/libunwind/src/UnwindLevel1.c b/libunwind/src/UnwindLevel1.c
index 7e785f4d31e71..e63f22906f5d6 100644
--- a/libunwind/src/UnwindLevel1.c
+++ b/libunwind/src/UnwindLevel1.c
@@ -507,6 +507,10 @@ _Unwind_ForcedUnwind(_Unwind_Exception *exception_object,
                        (void *)exception_object, (void *)(uintptr_t)stop);
   unw_context_t uc;
   unw_cursor_t cursor;
+#if __has_feature(memory_sanitizer)
+  __builtin_memset(&uc, 0, sizeof(uc));
+  __builtin_memset(&cursor, 0, sizeof(cursor));
+#endif
   __unw_getcontext(&uc);
 
   // Mark that this is a forced unwind, so _Unwind_Resume() can do
diff --git a/libunwind/test/forceunwind.pass.cpp b/libunwind/test/forceunwind.pass.cpp
index 344034e1ea5f5..e8333eb74a979 100644
--- a/libunwind/test/forceunwind.pass.cpp
+++ b/libunwind/test/forceunwind.pass.cpp
@@ -9,9 +9,6 @@
 
 // REQUIRES: linux
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 // Basic test for _Unwind_ForcedUnwind.
 // See libcxxabi/test/forced_unwind* tests too.
 
diff --git a/libunwind/test/libunwind_01.pass.cpp b/libunwind/test/libunwind_01.pass.cpp
index 838df6b589720..d5fd7fbbf05f7 100644
--- a/libunwind/test/libunwind_01.pass.cpp
+++ b/libunwind/test/libunwind_01.pass.cpp
@@ -10,19 +10,16 @@
 // TODO: Investigate this failure on x86_64 macOS back deployment
 // XFAIL: stdlib=system && target=x86_64-apple-macosx{{10.9|10.10|10.11|10.12|10.13|10.14|10.15|11.0|12.0}}
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 #include <libunwind.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 
 void backtrace(int lower_bound) {
-  unw_context_t context;
+  unw_context_t context = {0};
   unw_getcontext(&context);
 
-  unw_cursor_t cursor;
+  unw_cursor_t cursor = {0};
   unw_init_local(&cursor, &context);
 
   char buffer[1024];
@@ -67,10 +64,10 @@ __attribute__((noinline)) void test3(int i, int j, int k) {
 }
 
 void test_no_info() {
-  unw_context_t context;
+  unw_context_t context = {0};
   unw_getcontext(&context);
 
-  unw_cursor_t cursor;
+  unw_cursor_t cursor = {0};
   unw_init_local(&cursor, &context);
 
   unw_proc_info_t info;
@@ -87,10 +84,10 @@ void test_no_info() {
 }
 
 void test_reg_names() {
-  unw_context_t context;
+  unw_context_t context = {0};
   unw_getcontext(&context);
 
-  unw_cursor_t cursor;
+  unw_cursor_t cursor = {0};
   unw_init_local(&cursor, &context);
 
   int max_reg_num = -100;
@@ -113,7 +110,7 @@ void test_reg_names() {
 
 #if defined(__x86_64__)
 void test_reg_get_set() {
-  unw_context_t context;
+  unw_context_t context = {0};
   unw_getcontext(&context);
 
   unw_cursor_t cursor;
@@ -134,10 +131,10 @@ void test_reg_get_set() {
 }
 
 void test_fpreg_get_set() {
-  unw_context_t context;
+  unw_context_t context = {0};
   unw_getcontext(&context);
 
-  unw_cursor_t cursor;
+  unw_cursor_t cursor = {0};
   unw_init_local(&cursor, &context);
 
   // get/set is not implemented for x86_64 fpregs.
diff --git a/libunwind/test/libunwind_02.pass.cpp b/libunwind/test/libunwind_02.pass.cpp
index 9fd8e5d7159c9..5f2d2b43bddc1 100644
--- a/libunwind/test/libunwind_02.pass.cpp
+++ b/libunwind/test/libunwind_02.pass.cpp
@@ -7,9 +7,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 // This test fails on older llvm, when built with picolibc.
 // XFAIL: clang-16 && LIBCXX-PICOLIBC-FIXME
 
diff --git a/libunwind/test/signal_frame.pass.cpp b/libunwind/test/signal_frame.pass.cpp
index 004029cfe1e90..2882b3fbf264b 100644
--- a/libunwind/test/signal_frame.pass.cpp
+++ b/libunwind/test/signal_frame.pass.cpp
@@ -12,9 +12,6 @@
 // TODO: Investigate this failure on Apple
 // XFAIL: target={{.+}}-apple-{{.+}}
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 // UNSUPPORTED: libunwind-arm-ehabi
 
 // The AIX assembler does not support CFI directives, which
@@ -32,8 +29,8 @@
 
 void test() {
   asm(".cfi_signal_frame");
-  unw_cursor_t cursor;
-  unw_context_t uc;
+  unw_cursor_t cursor = {0};
+  unw_context_t uc = {0};
   unw_getcontext(&uc);
   unw_init_local(&cursor, &uc);
   assert(unw_step(&cursor) > 0);
diff --git a/libunwind/test/signal_unwind.pass.cpp b/libunwind/test/signal_unwind.pass.cpp
index 1c1566415a4d4..8ba0c8b2859ac 100644
--- a/libunwind/test/signal_unwind.pass.cpp
+++ b/libunwind/test/signal_unwind.pass.cpp
@@ -10,9 +10,6 @@
 // Ensure that the unwinder can cope with the signal handler.
 // REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}}
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 // Note: this test fails on musl because:
 //
 //  (a) musl disables emission of unwind information for its build, and
diff --git a/libunwind/test/unw_resume.pass.cpp b/libunwind/test/unw_resume.pass.cpp
index 2b7470b5cad0e..45f34ac69ca09 100644
--- a/libunwind/test/unw_resume.pass.cpp
+++ b/libunwind/test/unw_resume.pass.cpp
@@ -10,14 +10,11 @@
 // Ensure that unw_resume() resumes execution at the stack frame identified by
 // cursor.
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 #include <libunwind.h>
 
 __attribute__((noinline)) void test_unw_resume() {
-  unw_context_t context;
-  unw_cursor_t cursor;
+  unw_context_t context = {0};
+  unw_cursor_t cursor = {0};
 
   unw_getcontext(&context);
   unw_init_local(&cursor, &context);
diff --git a/libunwind/test/unwind_leaffunction.pass.cpp b/libunwind/test/unwind_leaffunction.pass.cpp
index 98de7dc43260c..4259406cc493d 100644
--- a/libunwind/test/unwind_leaffunction.pass.cpp
+++ b/libunwind/test/unwind_leaffunction.pass.cpp
@@ -10,9 +10,6 @@
 // Ensure that leaf function can be unwund.
 // REQUIRES: target={{(aarch64|riscv64|s390x|x86_64)-.+linux.*}}
 
-// TODO: Figure out why this fails with Memory Sanitizer.
-// XFAIL: msan
-
 // Note: this test fails on musl because:
 //
 //  (a) musl disables emission of unwind information for its build, and