diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-08-06 19:38:55 +0200 |
|---|---|---|
| committer | Kamal Mostafa <kamal@canonical.com> | 2013-08-21 10:58:19 -0700 |
| commit | 2bad891b281ea00ffa4bf768f217bb6bee16997d (patch) | |
| tree | e2bc459ba48bd35026052fe1789692bf2bc89cc1 | |
| parent | 457880cca5211e8156b36158ef6546b9c08c17ef (diff) | |
userns: unshare_userns(&cred) should not populate cred on failure
commit 6160968cee8b90a5dd95318d716e31d7775c4ef3 upstream.
unshare_userns(new_cred) does *new_cred = prepare_creds() before
create_user_ns() which can fail. However, the caller expects that
it doesn't need to take care of new_cred if unshare_userns() fails.
We could change the single caller, sys_unshare(), but I think it
would be more clean to avoid the side effects on failure, so with
this patch unshare_userns() does put_cred() itself and initializes
*new_cred only if create_user_ns() succeeeds.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
| -rw-r--r-- | kernel/user_namespace.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index f359dc7fb8c5..38ae0f5ee564 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -105,16 +105,21 @@ int create_user_ns(struct cred *new) int unshare_userns(unsigned long unshare_flags, struct cred **new_cred) { struct cred *cred; + int err = -ENOMEM; if (!(unshare_flags & CLONE_NEWUSER)) return 0; cred = prepare_creds(); - if (!cred) - return -ENOMEM; + if (cred) { + err = create_user_ns(cred); + if (err) + put_cred(cred); + else + *new_cred = cred; + } - *new_cred = cred; - return create_user_ns(cred); + return err; } void free_user_ns(struct kref *kref) |