From 1328c727004d432bbdfba0ffa02a166df04c7305 Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Thu, 26 Jan 2017 14:33:46 -0600 Subject: [PATCH] vfs: open() with O_CREAT should not create inodes with unknown ids may_create() rejects creation of inodes with ids which lack a mapping into s_user_ns. However for O_CREAT may_o_create() is is used instead. Add a similar check there. Fixes: 036d523641c6 ("vfs: Don't create inodes with a uid or gid unknown to the vfs") Signed-off-by: Seth Forshee Signed-off-by: "Eric W. Biederman" --- fs/namei.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/namei.c b/fs/namei.c index ad74877e1442..6fa3e9138fe4 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2941,10 +2941,16 @@ static inline int open_to_namei_flags(int flag) static int may_o_create(const struct path *dir, struct dentry *dentry, umode_t mode) { + struct user_namespace *s_user_ns; int error = security_path_mknod(dir, dentry, mode, 0); if (error) return error; + s_user_ns = dir->dentry->d_sb->s_user_ns; + if (!kuid_has_mapping(s_user_ns, current_fsuid()) || + !kgid_has_mapping(s_user_ns, current_fsgid())) + return -EOVERFLOW; + error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); if (error) return error; -- 2.20.1