From 55956b59df336f6738da916dbb520b6e37df9fbd Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 23 May 2018 15:24:18 -0500 Subject: vfs: Allow userns root to call mknod on owned filesystems. These filesystems already always set SB_I_NODEV so mknod will not be useful for gaining control of any devices no matter their permissions. This will allow overlayfs and applications like to fakeroot to use device nodes to represent things on disk. Acked-by: Seth Forshee Signed-off-by: "Eric W. Biederman" --- fs/namei.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/namei.c') diff --git a/fs/namei.c b/fs/namei.c index 942c1f096f6b..20335896dcce 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3679,7 +3679,8 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) if (error) return error; - if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) + if ((S_ISCHR(mode) || S_ISBLK(mode)) && + !ns_capable(dentry->d_sb->s_user_ns, CAP_MKNOD)) return -EPERM; if (!dir->i_op->mknod) -- cgit