From: Seth Forshee Date: Sat, 7 Oct 2017 22:36:55 +0000 (+0000) Subject: vfs: open() with O_CREAT should not create inodes with unknown ids X-Git-Tag: archive/raspbian/4.9.80-2+rpi1~7^2~1452 X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=2e727b8abeeb0e4144902cbb485311ad54272601;p=linux-4.9.git vfs: open() with O_CREAT should not create inodes with unknown ids [ Upstream commit 1328c727004d432bbdfba0ffa02a166df04c7305 ] 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" Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/namei.c b/fs/namei.c index 66209f720146..e7d125c23aa6 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2971,10 +2971,16 @@ 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;