[PATCH 01/43] vfs: Don't allow a user namespace root to make device nodes

"Eric W. Beiderman
2012-04-08T05:12:15Z

From: Eric W. Biederman <ebiederm@xmission.com>

Safely making device nodes in a container is solvable but simply
having the capability in a user namespace is not sufficient to make
this work.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
fs/namei.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 1898198..701954d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2560,8 +2560,7 @@ 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)) &&
- !ns_capable(inode_userns(dir), CAP_MKNOD))
+ if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
return -EPERM;

if (!dir->i_op->mknod)
--
1.7.2.5