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Groups > linux.kernel > #1685937
| From | Vivek Goyal <vgoyal@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2] xattr: Enable security.capability in user namespaces |
| Date | 2017-07-12 20:00 +0200 |
| Message-ID | <u2u5A-2Sc-1@gated-at.bofh.it> (permalink) |
| References | <u24Xv-3TD-3@gated-at.bofh.it> <u24Xv-3TD-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Jul 11, 2017 at 11:05:11AM -0400, Stefan Berger wrote:
[..]
> @@ -301,14 +721,39 @@ ssize_t
> __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
> void *value, size_t size)
> {
> - const struct xattr_handler *handler;
> + const struct xattr_handler *handler = NULL;
> + char *newname = NULL;
> + int ret, userns_supt_xattr;
> + struct user_namespace *userns = current_user_ns();
> +
> + userns_supt_xattr = (xattr_is_userns_supported(name, false) >= 0);
> +
Hi Stephan,
> + do {
> + kfree(newname);
> +
> + newname = xattr_userns_name(name, userns);
^^^
Will name be pointing to a freed string in second iteration of loop.
> + if (IS_ERR(newname))
> + return PTR_ERR(newname);
> +
> + if (!handler) {
> + name = newname;
Here we assign name and at the beginning of second iteration we free
newname.
Also I am not sure why do we do this assignment only if handler is NULL.
BTW, I set cap_sys_admin on a file outside usernamespace and then launched
user namespace (mapping 1000 to 0). And then tried to do getcap on file
and I am not seeing security.capability set by host. Not sure what am I
doing wrong. getxattr() seems to return -ENODATA. Still debugging it.
Also, have we resovled the question of stacked filesystem like overlayfs.
There we are switching creds to mounter's creds when doing operations on
underlying filesystem. I am concenrned does that mean, we will get and
return security.capability to caller in usernamespace instead of
security.capability@uid=1000.
Vivek
> + handler = xattr_resolve_name(inode, &name);
> + if (IS_ERR(handler)) {
> + ret = PTR_ERR(handler);
> + goto out;
> + }
> + if (!handler->get) {
> + ret = -EOPNOTSUPP;
> + goto out;
> + }
> + }
> + ret = handler->get(handler, dentry, inode, name, value, size);
> + userns = userns->parent;
> + } while ((ret == -ENODATA) && userns && userns_supt_xattr);
>
> - handler = xattr_resolve_name(inode, &name);
> - if (IS_ERR(handler))
> - return PTR_ERR(handler);
> - if (!handler->get)
> - return -EOPNOTSUPP;
> - return handler->get(handler, dentry, inode, name, value, size);
> +out:
> + kfree(newname);
> + return ret;
> }
> EXPORT_SYMBOL(__vfs_getxattr);
>
Thanks
Vivek
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[PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <"Stefan Bergerstefanb"@linux.vnet.ibm.com> - 2017-07-11 17:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-11 19:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-12 02:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-12 02:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-12 05:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-12 13:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-12 19:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces James Morris <jmorris@namei.org> - 2017-07-12 10:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-12 15:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-12 19:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces James Morris <jmorris@namei.org> - 2017-07-13 00:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 02:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 03:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 01:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-13 02:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Theodore Ts'o <tytso@mit.edu> - 2017-07-13 03:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 04:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 14:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Theodore Ts'o <tytso@mit.edu> - 2017-07-13 18:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-13 19:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 19:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Theodore Ts'o <tytso@mit.edu> - 2017-07-13 21:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 21:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 23:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces James Morris <jmorris@namei.org> - 2017-07-18 09:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 19:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-13 19:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 20:00 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 21:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-13 23:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-14 02:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-14 13:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-14 14:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-14 14:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-14 15:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-14 17:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-14 19:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-14 20:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-07-14 20:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces James Bottomley <James.Bottomley@HansenPartnership.com> - 2017-07-14 21:00 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-07-14 22:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces James Bottomley <James.Bottomley@HansenPartnership.com> - 2017-07-14 22:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Theodore Ts'o <tytso@mit.edu> - 2017-07-14 23:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-15 01:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-07-15 01:40 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-15 02:10 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Theodore Ts'o <tytso@mit.edu> - 2017-07-14 21:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-07-14 21:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-07-14 21:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-15 02:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Mimi Zohar <zohar@linux.vnet.ibm.com> - 2017-07-16 13:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-14 21:00 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-14 21:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 23:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 23:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces "Serge E. Hallyn" <serge@hallyn.com> - 2017-07-13 02:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Vivek Goyal <vgoyal@redhat.com> - 2017-07-12 20:00 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-12 21:20 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces ebiederm@xmission.com (Eric W. Biederman) - 2017-07-15 01:50 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-15 23:30 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Vivek Goyal <vgoyal@redhat.com> - 2017-07-17 21:00 +0200
Re: [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger <stefanb@linux.vnet.ibm.com> - 2017-07-17 23:00 +0200
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