lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 6 Aug 2013 11:14:24 -0700 From: Andy Lutomirski <luto@...capital.net> To: Oleg Nesterov <oleg@...hat.com> Cc: security@...nel.org, oss-security@...ts.openwall.com, Petr Matousek <pmatouse@...hat.com>, "Eric W. Biederman" <ebiederm@...ssion.com>, David Howells <dhowells@...hat.com>, linux-kernel@...r.kernel.org Subject: Re: [PATCH 1/1] userns: unshare_userns(&cred) should not populate cred on failure On Tue, Aug 6, 2013 at 10:38 AM, Oleg Nesterov <oleg@...hat.com> wrote: > 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. > > Cc: stable@...r.kernel.org > Signed-off-by: Oleg Nesterov <oleg@...hat.com> > --- > 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 d8c30db..6e50a44 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 user_namespace *ns) > -- > 1.5.5.1 > > Reviewed-by: Andy Lutomirski <luto@...capital.net> -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists