Index: lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -6566,6 +6566,46 @@
 #define INIT_FACCESSAT
 #endif
 
+#if SANITIZER_INTERCEPT_GETGROUPLIST
+INTERCEPTOR(int, getgrouplist, const char *name, u32 basegid, u32 *groups,
+            int *ngroups) {
+  void *ctx;
+  int res;
+  COMMON_INTERCEPTOR_ENTER(ctx, getgrouplist, name, basegid, groups, ngroups);
+  if (name)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
+  if (ngroups)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, ngroups, sizeof(*ngroups));
+  res = REAL(getgrouplist)(name, basegid, groups, ngroups);
+  if (!res && groups && ngroups) {
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, groups, sizeof(*groups) * (*ngroups));
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ngroups, sizeof(*ngroups));
+  }
+  return res;
+}
+
+INTERCEPTOR(int, getgroupmembership, const char *name, u32 basegid, u32 *groups,
+            int maxgrp, int *ngroups) {
+  void *ctx;
+  int res;
+  COMMON_INTERCEPTOR_ENTER(ctx, getgroupmembership, name, basegid, groups, maxgrp, ngroups);
+  if (name)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
+  res = REAL(getgroupmembership)(name, basegid, groups, maxgrp, ngroups);
+  if (!res && groups && ngroups) {
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, groups, sizeof(*groups) * (*ngroups));
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ngroups, sizeof(*ngroups));
+  }
+  return res;
+}
+
+#define INIT_GETGROUPLIST \
+  COMMON_INTERCEPT_FUNCTION(getgrouplist); \
+  COMMON_INTERCEPT_FUNCTION(getgroupmembership);
+#else
+#define INIT_GETGROUPLIST
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();
@@ -6784,6 +6824,7 @@
   INIT_GID_FROM_GROUP;
   INIT_ACCESS;
   INIT_FACCESSAT;
+  INIT_GETGROUPLIST;
 
 #if SANITIZER_NETBSD
   COMMON_INTERCEPT_FUNCTION(__libc_mutex_lock);
Index: lib/sanitizer_common/sanitizer_platform_interceptors.h
===================================================================
--- lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -439,5 +439,6 @@
 #define SANITIZER_INTERCEPT_GID_FROM_GROUP SI_NETBSD
 #define SANITIZER_INTERCEPT_ACCESS SI_NETBSD
 #define SANITIZER_INTERCEPT_FACCESSAT SI_NETBSD
+#define SANITIZER_INTERCEPT_GETGROUPLIST SI_NETBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H
Index: test/sanitizer_common/TestCases/NetBSD/getgrouplist.cc
===================================================================
--- test/sanitizer_common/TestCases/NetBSD/getgrouplist.cc
+++ test/sanitizer_common/TestCases/NetBSD/getgrouplist.cc
@@ -0,0 +1,29 @@
+// RUN: %clangxx -O0 -g %s -o %t && %run %t
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <grp.h>
+
+int main(void) {
+  gid_t *groups;
+  gid_t nobody;
+  int ngroups;
+
+  ngroups = sysconf(_SC_NGROUPS_MAX);
+  groups = (gid_t *)malloc(ngroups * sizeof(gid_t));
+  if (!groups)
+    exit(1);
+
+  if (gid_from_group("nobody", &nobody) == -1)
+    exit(1);
+
+  if (getgrouplist("nobody", nobody, groups, &ngroups))
+    exit(1);
+
+  if (groups && ngroups) {
+    free(groups);
+    exit(0);
+  }
+
+  return -1;
+}
Index: test/sanitizer_common/TestCases/NetBSD/getgroupmembership.cc
===================================================================
--- test/sanitizer_common/TestCases/NetBSD/getgroupmembership.cc
+++ test/sanitizer_common/TestCases/NetBSD/getgroupmembership.cc
@@ -0,0 +1,30 @@
+// RUN: %clangxx -O0 -g %s -o %t && %run %t
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <grp.h>
+
+int main(void) {
+  gid_t *groups;
+  gid_t nobody;
+  int ngroups;
+  int maxgrp;
+
+  maxgrp = sysconf(_SC_NGROUPS_MAX);
+  groups = (gid_t *)malloc(maxgrp * sizeof(gid_t));
+  if (!groups)
+    exit(1);
+
+  if (gid_from_group("nobody", &nobody) == -1)
+    exit(1);
+
+  if (getgroupmembership("nobody", nobody, groups, maxgrp, &ngroups))
+    exit(1);
+
+  if (groups && ngroups) {
+    free(groups);
+    exit(0);
+  }
+
+  return -1;
+}