testcases runable as root

[apt.git] / apt-pkg / contrib / fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 8e7313e8fcca69d3557d2b1cfc975a976cfc05af..f6351b7b5dc9372a8b051603743cdcc1a90ed9cd 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -857,11 +857,7 @@ bool ExecWait(pid_t Pid,const char *Name,bool Reap)
    return true;
 }
                                                                        /*}}}*/
    return true;
 }
                                                                        /*}}}*/

-
-
-// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned     /*{{{*/
-// ---------------------------------------------------------------------
-/* */
+// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned    /*{{{*/

 bool StartsWithGPGClearTextSignature(string const &FileName)
 {
    static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----\n";
 bool StartsWithGPGClearTextSignature(string const &FileName)
 {
    static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----\n";


@@ -877,7 +873,7 @@ bool StartsWithGPGClearTextSignature(string const &FileName)
 
    return true;
 }
 
    return true;
 }

-
+                                                                       /*}}}*/

 
 class FileFdPrivate {                                                  /*{{{*/
        public:
 
 class FileFdPrivate {                                                  /*{{{*/
        public:


@@ -896,7 +892,7 @@ class FileFdPrivate {                                                       /*{{{*/
           bool eof;
           bool compressing;
 
           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)
              {
           ~LZMAFILE() {
              if (compressing == true)
              {


@@ -1525,7 +1521,7 @@ bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual)
            int err;
            char const * const errmsg = BZ2_bzerror(d->bz2, &err);
            if (err != BZ_IO_ERROR)
            int err;
            char const * const errmsg = BZ2_bzerror(d->bz2, &err);
            if (err != BZ_IO_ERROR)

-              return FileFdError("BZ2_bzread: %s (%d: %s)", _("Read error"), err, errmsg);
+              return FileFdError("BZ2_bzread: %s %s (%d: %s)", FileName.c_str(), _("Read error"), err, errmsg);

         }
 #endif
 #ifdef HAVE_LZMA
         }
 #endif
 #ifdef HAVE_LZMA


@@ -2035,10 +2031,7 @@ APT_DEPRECATED gzFile FileFd::gzFd() {
 #endif
 }
 
 #endif
 }
 

-
-// Glob - wrapper around "glob()"                                      /*{{{*/
-// ---------------------------------------------------------------------
-/* */
+// Glob - wrapper around "glob()"                                      /*{{{*/

 std::vector<std::string> Glob(std::string const &pattern, int flags)
 {
    std::vector<std::string> result;
 std::vector<std::string> Glob(std::string const &pattern, int flags)
 {
    std::vector<std::string> result;


@@ -2064,8 +2057,7 @@ std::vector<std::string> Glob(std::string const &pattern, int flags)
    return result;
 }
                                                                        /*}}}*/
    return result;
 }
                                                                        /*}}}*/

-
-std::string GetTempDir()
+std::string GetTempDir()                                               /*{{{*/

 {
    const char *tmpdir = getenv("TMPDIR");
 
 {
    const char *tmpdir = getenv("TMPDIR");
 


@@ -2081,8 +2073,8 @@ std::string GetTempDir()
 
    return string(tmpdir);
 }
 
    return string(tmpdir);
 }

-
-FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)
+                                                                       /*}}}*/
+FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)   /*{{{*/

 {
    char fn[512];
    FileFd *Fd = new FileFd();
 {
    char fn[512];
    FileFd *Fd = new FileFd();


@@ -2106,19 +2098,19 @@ FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink)
 
    return Fd;
 }
 
    return Fd;
 }

-
-bool Rename(std::string From, std::string To)
+                                                                       /*}}}*/
+bool Rename(std::string From, std::string To)                          /*{{{*/

 {
    if (rename(From.c_str(),To.c_str()) != 0)
    {
       _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
                     From.c_str(),To.c_str());
       return false;
 {
    if (rename(From.c_str(),To.c_str()) != 0)
    {
       _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
                     From.c_str(),To.c_str());
       return false;

-   }   
+   }

    return true;
 }
    return true;
 }

-
-bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)
+                                                                       /*}}}*/
+bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/*{{{*/

 {
    int fd;
    if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)
 {
    int fd;
    if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)


@@ -2126,10 +2118,8 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)
 
    int Pipe[2] = {-1, -1};
    if(pipe(Pipe) != 0)
 
    int Pipe[2] = {-1, -1};
    if(pipe(Pipe) != 0)

-   {

       return _error->Errno("pipe", _("Failed to create subprocess IPC"));
       return _error->Errno("pipe", _("Failed to create subprocess IPC"));

-      return NULL;
-   }
+

    std::set<int> keep_fds;
    keep_fds.insert(Pipe[0]);
    keep_fds.insert(Pipe[1]);
    std::set<int> keep_fds;
    keep_fds.insert(Pipe[0]);
    keep_fds.insert(Pipe[1]);


@@ -2172,31 +2162,42 @@ bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)
 
    return true;
 }
 
    return true;
 }

-
-bool DropPrivs()
+                                                                       /*}}}*/
+bool DropPrivileges()                                                  /*{{{*/

 {
 {

-   /* uid will be 0 in the end, but gid might be different anyway */
-   uid_t old_uid = getuid();
-   gid_t old_gid = getgid();
-
-   if (old_uid != 0)
-      return true;

    if(_config->FindB("Debug::NoDropPrivs", false) == true)
       return true;
 
    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());
-   if (pw == NULL)
-      return _error->Warning("No user %s, can not drop rights", nobody.c_str());
+   // empty setting disables DropPrivilidges - this also ensures
+   // backward compatibility, see bug #764506
+   const std::string toUser = _config->Find("APT::Sandbox::User");
+   if (toUser.empty())
+      return true;

 
 #if __gnu_linux__
 
 #if __gnu_linux__

-   // see prctl(2), needs linux3.5
-   int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0,0, 0);
-   if(ret < 0)
+#if defined(PR_SET_NO_NEW_PRIVS) && ( PR_SET_NO_NEW_PRIVS != 38 )
+#error "PR_SET_NO_NEW_PRIVS is defined, but with a different value than expected!"
+#endif
+   // see prctl(2), needs linux3.5 at runtime - magic constant to avoid it at buildtime
+   int ret = prctl(38, 1, 0, 0, 0);
+   // ignore EINVAL - kernel is too old to understand the option
+   if(ret < 0 && errno != EINVAL)

       _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
 #endif
 
       _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
 #endif
 

-   if (setgroups(1, &pw->pw_gid) != 1)
+   // uid will be 0 in the end, but gid might be different anyway
+   uid_t const old_uid = getuid();
+   gid_t const old_gid = getgid();
+
+   if (old_uid != 0)
+      return true;
+
+   struct passwd *pw = getpwnam(toUser.c_str());
+   if (pw == NULL)
+      return _error->Error("No user %s, can not drop rights", toUser.c_str());
+
+   // Do not change the order here, it might break things
+   if (setgroups(1, &pw->pw_gid))

       return _error->Errno("setgroups", "Failed to setgroups");
 
    if (setegid(pw->pw_gid) != 0)
       return _error->Errno("setgroups", "Failed to setgroups");
 
    if (setegid(pw->pw_gid) != 0)


@@ -2207,27 +2208,20 @@ bool DropPrivs()
 
    if (setuid(pw->pw_uid) != 0)
       return _error->Errno("setuid", "Failed to setuid");
 
    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
    // 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");
 
    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");
    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 (getgid() != pw->pw_gid)
       return _error->Error("Could not switch group");
    if (getegid() != pw->pw_gid)


@@ -2237,6 +2231,35 @@ bool DropPrivs()
    if (geteuid() != pw->pw_uid)
       return _error->Error("Could not switch effective user");
 
    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;
 }
    return true;
 }

+                                                                       /*}}}*/