>From 32f86740d27ef77160e438cd7dc4fcd5df159dd0 Mon Sep 17 00:00:00 2001 From: Serge E. Hallyn <serue@xxxxxxxxxx> Date: Tue, 17 Jul 2007 15:28:17 -0400 Subject: [PATCH 1/1] user namespace: fix copy_user_ns return value When a CONFIG_USER_NS=n and a user tries to unshare some namespace other than the user namespace, the dummy copy_user_ns returns NULL rather than the old_ns. This value then gets assigned to task->nsproxy->user_ns, so that a subsequent setuid, which uses task->nsproxy->user_ns, causes a NULL pointer deref. Fix this by returning old_ns. I believe this is a bug both in -mm and mainline. Signed-off-by: Serge E. Hallyn <serue@xxxxxxxxxx> --- include/linux/user_namespace.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index bb32057..1101b0c 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -49,7 +49,7 @@ static inline struct user_namespace *copy_user_ns(int flags, if (flags & CLONE_NEWUSER) return ERR_PTR(-EINVAL); - return NULL; + return old_ns; } static inline void put_user_ns(struct user_namespace *ns) -- 1.5.1.1.GIT _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
