Add new NetBSD interceptors: getgrouplist(3) & getgroupmembership(3)

[krytarowski]

Summary

getgrouplist, getgroupmembership -- calculate group access list

Sponsored by <The NetBSD Foundation>

[vitalybuka]

Could you please remove copied man page from the summary? Not sure about licences there.

[vitalybuka]

Tests?

lib/sanitizer_common/sanitizer_common_interceptors.inc

6476

you need COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ngroups... as well

6478

add empty line between interceptors

6488

same about ngroups

[krytarowski]

resolve comments from review

[krytarowski]

Tests from this revision require merged another patch in D42068

[vitalybuka]

test as is should be moved into sanitizer_common
However if we keep it here we can extend the test to check that it actually detects bugs. I am Ok with moving it into sanitizer_common

[krytarowski]

Move tests to sanitizer_common

lib/sanitizer_common/sanitizer_common_interceptors.inc

INTERCEPTOR(int, acct, const char *file) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, acct, file);
   if (file)
     COMMON_INTERCEPTOR_READ_RANGE(ctx, file, REAL(strlen)(file) + 1);
   return REAL(acct)(file);
 }
 #define INIT_ACCT COMMON_INTERCEPT_FUNCTION(acct)
 #else
 #define INIT_ACCT
 #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();
 
   INIT_TEXTDOMAIN;
   INIT_STRLEN;
   INIT_STRNLEN;
   INIT_STRNDUP;

lib/sanitizer_common/sanitizer_platform_interceptors.h

 #define SANITIZER_INTERCEPT_ALIGNED_ALLOC (!SI_MAC)
 #define SANITIZER_INTERCEPT_MALLOC_USABLE_SIZE (!SI_MAC)
 #define SANITIZER_INTERCEPT_MCHECK_MPROBE SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_WCSCAT SI_POSIX
 #define SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION (!SI_WINDOWS && SI_NOT_FUCHSIA)
 #define SANITIZER_INTERCEPT_BSD_SIGNAL SI_ANDROID
 
 #define SANITIZER_INTERCEPT_ACCT SI_NETBSD
+#define SANITIZER_INTERCEPT_GETGROUPLIST SI_NETBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H

test/msan/getgrouplist.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <grp.h>
+#include <stdlib.h>
+#include <unistd.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;
+}

test/msan/getgroupmembership.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <grp.h>
+#include <stdlib.h>
+#include <unistd.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;
+}