fixup! linux: switch to target process UID/GID

Author: mdavidsaver

ci_core_dumper/linux.py

@@ -95,6 +95,8 @@ def setns(F, nstype=0):
     # must open all NS files first (from init mount ns)
     # before entering any (including mount ns)
     for ns in os.listdir('/proc/%d/ns'%pid):
+        if ns not in ('mnt',):
+            continue
         NSs.append((ns,
                     open('/proc/%d/ns/%s'%(pid, ns), 'rb'),
                     open('/proc/self/ns/%s'%ns, 'rb')))
@@ -294,7 +296,7 @@ def dump(outdir, gdb, extra_cmds):
 
 def dump2(pid, gdb, extra_cmds):
     # running as root, fully in the target/container namespaces
-    print('Initial root is uid %d, gid %d'%(os.getuid(), os.getgid()))
+    print('Initial uid %d, gid %d'%(os.getuid(), os.getgid()))
 
     uid = gid = None
     with open('/proc/{}/status'.format(pid)) as F:
@@ -306,9 +308,9 @@ def dump2(pid, gdb, extra_cmds):
                 gid = int(line.split()[1])
 
     if gid:
-        os.setegid(gid)
+        os.setgid(gid)
     if uid:
-        os.seteuid(uid)
+        os.setuid(uid)
     print('Target UID %s/%s'%(uid, gid))
 
     # os.environ is still from the init namespaces.