From e38774dea8d0a23b952a423b4e7a946f0f570149 Mon Sep 17 00:00:00 2001
From: Jakub Filak <jfilak@redhat.com>
Date: Fri, 17 Apr 2015 14:42:13 +0200
Subject: [PATCH] ccpp: harden dealing with UID/GID

* Don't fall back to UID 0 (fixed in libreport)
* Use fsgid.

This issue was discovered by Florian Weimer of Red Hat Product Security.

Signed-off-by: Jakub Filak <jfilak@redhat.com>
---
 src/hooks/abrt-hook-ccpp.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/hooks/abrt-hook-ccpp.c b/src/hooks/abrt-hook-ccpp.c
index 9d9f549..92413e3 100644
--- a/src/hooks/abrt-hook-ccpp.c
+++ b/src/hooks/abrt-hook-ccpp.c
@@ -163,16 +163,13 @@ static DIR *open_cwd(pid_t pid)
     return cwd;
 }
 
-static int open_user_core(uid_t uid, uid_t fsuid, pid_t pid, char **percent_values)
+static int open_user_core(uid_t uid, uid_t fsuid, gid_t fsgid, pid_t pid, char **percent_values)
 {
     proc_cwd = open_cwd(pid);
     if (proc_cwd == NULL)
         return -1;
 
-    struct passwd* pw = getpwuid(uid);
-    gid_t gid = pw ? pw->pw_gid : uid;
-    //log("setting uid: %i gid: %i", uid, gid);
-    xsetegid(gid);
+    xsetegid(fsgid);
     xseteuid(fsuid);
 
     if (strcmp(core_basename, "core") == 0)
@@ -525,6 +522,10 @@ int main(int argc, char** argv)
     if (tmp_fsuid < 0)
         perror_msg_and_die("Can't parse 'Uid: line' in /proc/%lu/status", (long)pid);
 
+    const int fsgid = get_fsgid(proc_pid_status);
+    if (fsgid < 0)
+        error_msg_and_die("Can't parse 'Gid: line' in /proc/%lu/status", (long)pid);
+
     int suid_policy = dump_suid_policy();
     if (tmp_fsuid != uid)
     {
@@ -543,7 +544,7 @@ int main(int argc, char** argv)
     int user_core_fd = -1;
     if (setting_MakeCompatCore && ulimit_c != 0)
         /* note: checks "user_pwd == NULL" inside; updates core_basename */
-        user_core_fd = open_user_core(uid, fsuid, pid, &argv[1]);
+        user_core_fd = open_user_core(uid, fsuid, fsgid, pid, &argv[1]);
 
     if (executable == NULL)
     {
-- 
2.1.0