[compiler-rt] 1a729bc - [MSAN] add dn_expand intercept.

[Kevin Athey via llvm-commits]

Author: Kevin Athey
Date: 2022-06-03T09:49:42-07:00
New Revision: 1a729bce86173c9019545599c8a0771d0419ce9e

URL: https://github.com/llvm/llvm-project/commit/1a729bce86173c9019545599c8a0771d0419ce9e
DIFF: https://github.com/llvm/llvm-project/commit/1a729bce86173c9019545599c8a0771d0419ce9e.diff

LOG: [MSAN] add dn_expand intercept.

This interceptor only addresses writes to inputs.  Reads of inputs are not checked.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D126851

Added: 
    compiler-rt/test/msan/Linux/dn_expand.cpp
    compiler-rt/test/sanitizer_common/TestCases/Linux/dn_expand.cpp

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
    compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 3b316f5edea80..8a4594fb7dd41 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -2518,13 +2518,31 @@ INTERCEPTOR(int, __b64_pton, char const *src, char *target, SIZE_T targsize) {
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, target, res);
   return res;
 }
-#  define INIT___B64_TO                    \
+#define INIT___B64_TO                      \
     COMMON_INTERCEPT_FUNCTION(__b64_ntop); \
     COMMON_INTERCEPT_FUNCTION(__b64_pton);
 #else  // SANITIZER_INTERCEPT___B64_TO
 #define INIT___B64_TO
 #endif  // SANITIZER_INTERCEPT___B64_TO
 
+#if SANITIZER_INTERCEPT___DN_EXPAND
+  INTERCEPTOR(int, __dn_expand, unsigned char const *base,
+              unsigned char const *end, unsigned char const *src, char *dest,
+              int space) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, __dn_expand, base, end, src, dest, space);
+  // TODO: add read check if __dn_comp intercept added
+  int res = REAL(__dn_expand)(base, end, src, dest, space);
+  if (res >= 0)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dest, res + 1);
+  return res;
+}
+#define INIT___DN_EXPAND                    \
+    COMMON_INTERCEPT_FUNCTION(__dn_expand);
+#else  // SANITIZER_INTERCEPT___DN_EXPAND
+#define INIT___DN_EXPAND
+#endif  // SANITIZER_INTERCEPT___DN_EXPAND
+
 
 #if SANITIZER_INTERCEPT_POSIX_SPAWN
 
@@ -10427,6 +10445,7 @@ static void InitializeCommonInterceptors() {
   INIT_GLOB;
   INIT_GLOB64;
   INIT___B64_TO;
+  INIT___DN_EXPAND;
   INIT_POSIX_SPAWN;
   INIT_WAIT;
   INIT_WAIT4;

diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 8d31f5aeca9e0..12ced9505eb08 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -236,6 +236,7 @@
 #define SANITIZER_INTERCEPT_GLOB (SI_GLIBC || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_GLOB64 SI_GLIBC
 #define SANITIZER_INTERCEPT___B64_TO SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT___DN_EXPAND SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_POSIX_SPAWN SI_POSIX
 #define SANITIZER_INTERCEPT_WAIT SI_POSIX
 #define SANITIZER_INTERCEPT_INET SI_POSIX

diff  --git a/compiler-rt/test/msan/Linux/dn_expand.cpp b/compiler-rt/test/msan/Linux/dn_expand.cpp
new file mode 100644
index 0000000000000..5c8458000227b
--- /dev/null
+++ b/compiler-rt/test/msan/Linux/dn_expand.cpp
@@ -0,0 +1,42 @@
+// RUN: %clangxx_msan -O0 %s -o %t -lresolv && %run %t
+
+#include <assert.h>
+#include <resolv.h>
+#include <string.h>
+
+#include <sanitizer/msan_interface.h>
+
+void testWrite() {
+  char unsigned input[] = {0xff, 0xc5, 0xf7, 0xff, 0x00, 0x00, 0xff, 0x0a, 0x00,
+                           0x00, 0x00, 0x01, 0x00, 0x00, 0x02, 0x00, 0x01, 0x00,
+                           0x10, 0x01, 0x05, 0x00, 0x01, 0x0a, 0x67, 0x6f, 0x6f,
+                           0x67, 0x6c, 0x65, 0x2e, 0x63, 0x6f, 0x6d, 0x00};
+  char output[1024];
+
+  int res = dn_expand(input, input + sizeof(input), input + 23, output,
+                      sizeof(output));
+
+  assert(res >= 0);
+  __msan_check_mem_is_initialized(output, res);
+}
+
+void testWriteZeroLength() {
+  char unsigned input[] = {
+      0xff, 0xc5, 0xf7, 0xff, 0x00, 0x00, 0xff, 0x0a, 0x00, 0x00, 0x00, 0x01,
+      0x00, 0x00, 0x02, 0x00, 0x01, 0x00, 0x10, 0x01, 0x05, 0x00, 0x01, 0x00,
+  };
+  char output[1024];
+
+  int res = dn_expand(input, input + sizeof(input), input + 23, output,
+                      sizeof(output));
+
+  assert(res >= 0);
+  __msan_check_mem_is_initialized(output, res);
+}
+
+int main(int iArgc, const char *szArgv[]) {
+  testWrite();
+  testWriteZeroLength();
+
+  return 0;
+}

diff  --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/dn_expand.cpp b/compiler-rt/test/sanitizer_common/TestCases/Linux/dn_expand.cpp
new file mode 100644
index 0000000000000..eccdf728e7813
--- /dev/null
+++ b/compiler-rt/test/sanitizer_common/TestCases/Linux/dn_expand.cpp
@@ -0,0 +1,42 @@
+// RUN: %clangxx %s -o %t -lresolv && %run %t %p
+
+#include <assert.h>
+#include <resolv.h>
+#include <string.h>
+
+#include <sanitizer/msan_interface.h>
+
+void testWrite() {
+  char unsigned input[] = {0xff, 0xc5, 0xf7, 0xff, 0x00, 0x00, 0xff, 0x0a, 0x00,
+                           0x00, 0x00, 0x01, 0x00, 0x00, 0x02, 0x00, 0x01, 0x00,
+                           0x10, 0x01, 0x05, 0x00, 0x01, 0x0a, 0x67, 0x6f, 0x6f,
+                           0x67, 0x6c, 0x65, 0x2e, 0x63, 0x6f, 0x6d, 0x00};
+  char output[1024];
+
+  int res = dn_expand(input, input + sizeof(input), input + 23, output,
+                      sizeof(output));
+
+  assert(res == 12);
+  assert(strcmp(output, "google\\.com") == 0);
+}
+
+void testWriteZeroLength() {
+  char unsigned input[] = {
+      0xff, 0xc5, 0xf7, 0xff, 0x00, 0x00, 0xff, 0x0a, 0x00, 0x00, 0x00, 0x01,
+      0x00, 0x00, 0x02, 0x00, 0x01, 0x00, 0x10, 0x01, 0x05, 0x00, 0x01, 0x00,
+  };
+  char output[1024];
+
+  int res = dn_expand(input, input + sizeof(input), input + 23, output,
+                      sizeof(output));
+
+  assert(res == 1);
+  assert(strcmp(output, "") == 0);
+}
+
+int main(int iArgc, const char *szArgv[]) {
+  testWrite();
+  testWriteZeroLength();
+
+  return 0;
+}