3.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andy Lutomirski <[email protected]> commit 41c21e351e79004dbb4efa4bc14a53a7e0af38c5 upstream. 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 <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- kernel/user_namespace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -576,10 +576,10 @@ static ssize_t map_write(struct file *fi if (map->nr_extents != 0) goto out; - /* Require the appropriate privilege CAP_SETUID or CAP_SETGID - * over the user namespace in order to set the id mapping. + /* + * Adjusting namespace settings requires capabilities on the target. */ - if (cap_valid(cap_setid) && !ns_capable(ns, cap_setid)) + if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN)) goto out; /* Get a buffer */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
