Add new interceptors for pwcache(3)-style functions

[krytarowski]

Summary

From <pwd.h>: user_from_uid, uid_from_user

From <grp.h>: group_from_gid, gid_from_group

Sponsored by <The NetBSD Foundation>

[krytarowski]

• add tests
• correct interceptors

[krytarowski]

• correct typo

[vitalybuka]

test/msan/gid_from_group.cc

11

this is "common" change, so tests probably should be in sanitizer_common as well

[vitalybuka]

Please move tests into sanitizer_common

[vitalybuka]

ideally we should have these tests in sanitizer_common and run by all sanitizers
and "report" tests which check that interceptor actually validate arguments and unpoison results, e.g. tests for asan or msan

[krytarowski]

Move tests to sanitizer_common

[vitalybuka]

compiler-rt/trunk/test/sanitizer_common/TestCases/NetBSD/gid_from_group.cc

10 ↗

(On Diff #130383)

why exit and not just return 1, return 0?

[krytarowski]

compiler-rt/trunk/test/sanitizer_common/TestCases/NetBSD/gid_from_group.cc

10 ↗

(On Diff #130383)

I've followed other tests with this exit(3) call. I don't think it's worth the effort to change it.

lib/sanitizer_common/sanitizer_common_interceptors.inc

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_USER_FROM_UID
+INTERCEPTOR(const char *, user_from_uid, u32 uid, int nouser) {
+  void *ctx;
+  const char *user;
+  COMMON_INTERCEPTOR_ENTER(ctx, user_from_uid, uid, nouser);
+  user = REAL(user_from_uid)(uid, nouser);
+  if (user)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, user, REAL(strlen)(user) + 1);
+  return user;
+}
+#define INIT_USER_FROM_UID COMMON_INTERCEPT_FUNCTION(user_from_uid)
+#else
+#define INIT_USER_FROM_UID
+#endif
+
+#if SANITIZER_INTERCEPT_UID_FROM_USER
+INTERCEPTOR(int, uid_from_user, const char *name, u32 *uid) {
+  void *ctx;
+  int res;
+  COMMON_INTERCEPTOR_ENTER(ctx, uid_from_user, name, uid);
+  if (name)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, name, REAL(strlen)(name) + 1);
+  res = REAL(uid_from_user)(name, uid);
+  if (uid)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, uid, sizeof(*uid));
+  return ret;
+}
+#define INIT_UID_FROM_USER COMMON_INTERCEPT_FUNCTION(uid_from_user)
+#else
+#define INIT_UID_FROM_USER
+#endif
+
+#if SANITIZER_INTERCEPT_GROUP_FROM_GID
+INTERCEPTOR(const char *, group_from_gid, u32 gid, int nogroup) {
+  void *ctx;
+  const char *group;
+  COMMON_INTERCEPTOR_ENTER(ctx, group_from_gid, gid, nogroup);
+  group = REAL(group_from_gid)(gid, nogroup);
+  if (group)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, group, REAL(strlen)(group) + 1);
+  return group;
+}
+#define INIT_GROUP_FROM_GID COMMON_INTERCEPT_FUNCTION(group_from_gid)
+#else
+#define INIT_GROUP_FROM_GID
+#endif
+
+#if SANITIZER_INTERCEPT_GID_FROM_GROUP
+INTERCEPTOR(int, gid_from_group, const char *group, u32 *gid) {
+  void *ctx;
+  int res;
+  COMMON_INTERCEPTOR_ENTER(ctx, gid_from_group, group, gid);
+  if (group)
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, group, REAL(strlen)(group) + 1);
+  res = REAL(gid_from_group)(group, gid);
+  if (gid)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, gid, sizeof(*gid));
+  return ret;
+}
+#define INIT_GID_FROM_USER COMMON_INTERCEPT_FUNCTION(gid_from_group)
+#else
+#define INIT_GID_FROM_USER
+#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;
static void InitializeCommonInterceptors() {
   INIT___LXSTAT64;
   // FIXME: add other *stat interceptors.
   INIT_UTMP;
   INIT_UTMPX;
   INIT_GETLOADAVG;
   INIT_WCSLEN;
   INIT_WCSCAT;
   INIT_ACCT;
+  INIT_USER_FROM_UID;
+  INIT_UID_FROM_USER;
+  INIT_GROUP_FROM_GID;
+  INIT_GID_FROM_USER;
 
 #if SANITIZER_NETBSD
   COMMON_INTERCEPT_FUNCTION(__libc_mutex_lock);
   COMMON_INTERCEPT_FUNCTION(__libc_mutex_unlock);
   COMMON_INTERCEPT_FUNCTION(__libc_thr_setcancelstate);
 #endif
 
   INIT___PRINTF_CHK;
 }

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_USER_FROM_UID SI_NETBSD
+#define SANITIZER_INTERCEPT_UID_FROM_USER SI_NETBSD
+#define SANITIZER_INTERCEPT_GROUP_FROM_GID SI_NETBSD
+#define SANITIZER_INTERCEPT_GID_FROM_GROUP SI_NETBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H

test/msan/gid_from_group.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <grp.h>
+#include <stdlib.h>
+
+int main(void) {
+  gid_t nobody;
+
+  if (gid_from_group("nobody", &nobody) == -1)
+    exit(1);
+
+  if (nobody)
+    exit(0);
+
+  return 0;
+}

test/msan/group_from_gid.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <grp.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(void) {
+  const char *nobody;
+
+  if (!(nobody = group_from_gid(0, 0)))
+    exit(1);
+
+  if (strlen(nobody))
+    exit(0);
+
+  return 0;
+}

test/msan/uid_from_user.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <pwd.h>
+#include <stdlib.h>
+
+int main(void) {
+  uid_t nobody;
+
+  if (uid_from_user("nobody", &nobody) == -1)
+    exit(1);
+
+  if (nobody)
+    exit(0);
+
+  return 0;
+}

test/msan/user_from_uid.cc

+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+// UNSUPPORTED: linux
+
+#include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(void) {
+  const char *nobody;
+
+  if (!(nobody = user_from_uid(0, 0)))
+    exit(1);
+
+  if (strlen(nobody))
+    exit(0);
+
+  return 0;
+}