userns: Changing any namespace id mappings should require privileges
authorAndy Lutomirski <luto@amacapital.net>
Sun, 14 Apr 2013 18:44:04 +0000 (11:44 -0700)
committerAndy Lutomirski <luto@amacapital.net>
Mon, 15 Apr 2013 01:11:32 +0000 (18:11 -0700)
commit41c21e351e79004dbb4efa4bc14a53a7e0af38c5
tree09f41257304634a6f2dcf48fd99504924a5344f1
parente3211c120a85b792978bcb4be7b2886df18d27f0
userns: Changing any namespace id mappings should require privileges

Changing uid/gid/projid mappings doesn't change your id within the
namespace; it reconfigures the namespace.  Unprivileged programs should
*not* be able to write these files.  (We're also checking the privileges
on the wrong task.)

Given the write-once nature of these files and the other security
checks, this is likely impossible to usefully exploit.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
kernel/user_namespace.c