bool eof;
bool compressing;
- LZMAFILE() : file(NULL), eof(false), compressing(false) {}
+ LZMAFILE() : file(NULL), eof(false), compressing(false) { buffer[0] = '\0'; }
~LZMAFILE() {
if (compressing == true)
{
bool DropPrivs()
{
- /* uid will be 0 in the end, but gid might be different anyway */
+ // uid will be 0 in the end, but gid might be different anyway
uid_t old_uid = getuid();
gid_t old_gid = getgid();
if(_config->FindB("Debug::NoDropPrivs", false) == true)
return true;
- const std::string nobody = _config->Find("APT::User::Nobody", "_apt");
- struct passwd *pw = getpwnam(nobody.c_str());
+ const std::string toUser = _config->Find("APT::Sandbox::User", "_apt");
+ struct passwd *pw = getpwnam(toUser.c_str());
if (pw == NULL)
- return _error->Warning("No user %s, can not drop rights", nobody.c_str());
+ return _error->Error("No user %s, can not drop rights", toUser.c_str());
#if __gnu_linux__
// see prctl(2), needs linux3.5
if(ret < 0)
_error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
#endif
-
+ // Do not change the order here, it might break things
if (setgroups(1, &pw->pw_gid))
return _error->Errno("setgroups", "Failed to setgroups");
if (setuid(pw->pw_uid) != 0)
return _error->Errno("setuid", "Failed to setuid");
+
// the seteuid() is probably uneeded (at least thats what the linux
// man-page says about setuid(2)) but we cargo culted it anyway
-
-
if (seteuid(pw->pw_uid) != 0)
return _error->Errno("seteuid", "Failed to seteuid");
- /* Try changing GID/EGID */
- if (pw->pw_gid != old_gid && (setgid(old_gid) != -1 || setegid(old_gid) != -1))
- return _error->Error("Could restore a gid to root, privilege dropping did not work");
-
- if (pw->pw_uid != old_uid && (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
- return _error->Error("Could restore a uid to root, privilege dropping did not work");
-
- /* Verify the list of supplementary groups is what we expected */
+ // Verify that the user has only a single group, and the correct one
gid_t groups[1];
if (getgroups(1, groups) != 1)
return _error->Errno("getgroups", "Could not get new groups");
if (groups[0] != pw->pw_gid)
return _error->Error("Could not switch group");
- /* Verify gid, egid, uid, and euid */
+
+ // Verify that gid, egid, uid, and euid changed
if (getgid() != pw->pw_gid)
return _error->Error("Could not switch group");
if (getegid() != pw->pw_gid)
if (geteuid() != pw->pw_uid)
return _error->Error("Could not switch effective user");
- /* TODO: Check saved uid/saved gid as well */
+#ifdef HAVE_GETRESUID
+ // verify that the saved set-user-id was changed as well
+ uid_t ruid = 0;
+ uid_t euid = 0;
+ uid_t suid = 0;
+ if (getresuid(&ruid, &euid, &suid))
+ return _error->Errno("getresuid", "Could not get saved set-user-ID");
+ if (suid != pw->pw_uid)
+ return _error->Error("Could not switch saved set-user-ID");
+#endif
+
+#ifdef HAVE_GETRESGID
+ // verify that the saved set-group-id was changed as well
+ gid_t rgid = 0;
+ gid_t egid = 0;
+ gid_t sgid = 0;
+ if (getresgid(&rgid, &egid, &sgid))
+ return _error->Errno("getresuid", "Could not get saved set-group-ID");
+ if (sgid != pw->pw_gid)
+ return _error->Error("Could not switch saved set-group-ID");
+#endif
+
+ // Check that uid and gid changes do not work anymore
+ if (pw->pw_gid != old_gid && (setgid(old_gid) != -1 || setegid(old_gid) != -1))
+ return _error->Error("Could restore a gid to root, privilege dropping did not work");
+
+ if (pw->pw_uid != old_uid && (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
+ return _error->Error("Could restore a uid to root, privilege dropping did not work");
+
return true;
}