3.8.13.7 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Oleg Nesterov <[email protected]> commit 8742f229b635bf1c1c84a3dfe5e47c814c20b5c8 upstream. Ensure that user_namespace->parent chain can't grow too much. Currently we use the hardroded 32 as limit. Reported-by: Andy Lutomirski <[email protected]> Signed-off-by: Oleg Nesterov <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- include/linux/user_namespace.h | 1 + kernel/user_namespace.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index 5209cfe..e4539aa 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -23,6 +23,7 @@ struct user_namespace { struct uid_gid_map projid_map; struct kref kref; struct user_namespace *parent; + int level; kuid_t owner; kgid_t group; unsigned int proc_inum; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 38ae0f5..b9b0b51 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -62,6 +62,9 @@ int create_user_ns(struct cred *new) kgid_t group = new->egid; int ret; + if (parent_ns->level > 32) + return -EUSERS; + /* * Verify that we can not violate the policy of which files * may be accessed that is specified by the root directory, @@ -92,6 +95,7 @@ int create_user_ns(struct cred *new) kref_init(&ns->kref); /* Leave the new->user_ns reference with the new user namespace. */ ns->parent = parent_ns; + ns->level = parent_ns->level + 1; ns->owner = owner; ns->group = group; -- 1.8.1.2 -- 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/
