From fc1a78d8e9b958f3d65fe1c03494d785314f9816 Mon Sep 17 00:00:00 2001
From: Michael Vogt <mvo@debian.org>
Date: Wed, 11 Jun 2014 15:31:38 +0200
Subject: DropPrivs in the solvers (just to be on the safe side)

---
 apt-pkg/contrib/fileutl.cc     | 17 +++++++++++++++++
 apt-pkg/contrib/fileutl.h      |  3 +++
 cmdline/apt-dump-solver.cc     |  2 ++
 cmdline/apt-internal-solver.cc |  3 +++
 4 files changed, 25 insertions(+)

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 1ba4674e5..da81edbcc 100644
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -47,6 +47,7 @@
 #include <signal.h>
 #include <errno.h>
 #include <glob.h>
+#include <pwd.h>
 
 #include <set>
 #include <algorithm>
@@ -2050,3 +2051,19 @@ bool Rename(std::string From, std::string To)
    }   
    return true;
 }
+
+bool DropPrivs()
+{
+   if (getuid() != 0)
+      return true;
+
+   const std::string nobody = _config->Find("APT::User::Nobody", "nobody");
+   struct passwd *pw = getpwnam(nobody.c_str());
+   if (pw == NULL)
+      return _error->Warning("No user %s, can not drop rights", nobody.c_str());
+   if (setgid(pw->pw_gid) != 0)
+      return _error->Errno("setgid", "Failed to setgid");
+   if (setuid(pw->pw_uid) != 0)
+      return _error->Errno("setuid", "Failed to setuid");
+   return true;
+}
diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h
index cc1a98eae..683c04157 100644
--- a/apt-pkg/contrib/fileutl.h
+++ b/apt-pkg/contrib/fileutl.h
@@ -191,6 +191,9 @@ pid_t ExecFork(std::set<int> keep_fds);
 void MergeKeepFdsFromConfiguration(std::set<int> &keep_fds);
 bool ExecWait(pid_t Pid,const char *Name,bool Reap = false);
 
+// process releated
+bool DropPrivs();
+
 // File string manipulators
 std::string flNotDir(std::string File);
 std::string flNotFile(std::string File);
diff --git a/cmdline/apt-dump-solver.cc b/cmdline/apt-dump-solver.cc
index 04e13bde9..424764b3c 100644
--- a/cmdline/apt-dump-solver.cc
+++ b/cmdline/apt-dump-solver.cc
@@ -40,6 +40,8 @@ int main(int argc,const char *argv[])					/*{{{*/
 		ShowHelp();
 		return 0;
 	}
+        // we really don't need anything
+        DropPrivs();
 
 	FILE* input = fdopen(STDIN_FILENO, "r");
 	FILE* output = fopen("/tmp/dump.edsp", "w");
diff --git a/cmdline/apt-internal-solver.cc b/cmdline/apt-internal-solver.cc
index e4cdf6381..0cac12da2 100644
--- a/cmdline/apt-internal-solver.cc
+++ b/cmdline/apt-internal-solver.cc
@@ -74,6 +74,9 @@ int main(int argc,const char *argv[])					/*{{{*/
 		{'o',"option",0,CommandLine::ArbItem},
 		{0,0,0,0}};
 
+        // we really don't need anything
+        DropPrivs();
+
 	CommandLine CmdL(Args,_config);
 	if (pkgInitConfig(*_config) == false ||
 	    CmdL.Parse(argc,argv) == false) {
-- 
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