Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1285965

[PATCH v2 09/18] fs: Refuse uid/gid changes which don't map into s_user_ns

From Seth Forshee <seth.forshee@canonical.com>
Newsgroups linux.kernel
Subject [PATCH v2 09/18] fs: Refuse uid/gid changes which don't map into s_user_ns
Date 2015-12-07 22:40 +0100
Message-ID <qDbFM-1D6-25@gated-at.bofh.it> (permalink)
References <qDbw5-1y2-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Add checks to inode_change_ok to verify that uid and gid changes
will map into the superblock's user namespace. If they do not
fail with -EOVERFLOW. This cannot be overriden with ATTR_FORCE.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
---
 fs/attr.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/attr.c b/fs/attr.c
index 6530ced19697..55b46e3aa888 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -42,6 +42,17 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr)
 			return error;
 	}
 
+	/*
+	 * Verify that uid/gid changes are valid in the target namespace
+	 * of the superblock. This cannot be overriden using ATTR_FORCE.
+	 */
+	if (ia_valid & ATTR_UID &&
+	    from_kuid(inode->i_sb->s_user_ns, attr->ia_uid) == (uid_t)-1)
+		return -EOVERFLOW;
+	if (ia_valid & ATTR_GID &&
+	    from_kgid(inode->i_sb->s_user_ns, attr->ia_gid) == (gid_t)-1)
+		return -EOVERFLOW;
+
 	/* If force is set do it anyway. */
 	if (ia_valid & ATTR_FORCE)
 		return 0;
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v2 00/19] Support fuse mounts in user namespaces Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:30 +0100
  [PATCH v2 15/18] fuse: Add support for pid namespaces Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:30 +0100
  [PATCH v2 13/18] fs: Allow superblock owner to access do_remount_sb() Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:30 +0100
  [PATCH v2 17/18] fuse: Restrict allow_other to the superblock's namespace or a descendant Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:30 +0100
  [PATCH v2 10/18] fs: Update posix_acl support to handle user namespace mounts Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:30 +0100
  [PATCH v2 04/18] selinux: Add support for unprivileged mounts from user namespaces Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:40 +0100
  [PATCH v2 05/18] userns: Replace in_userns with current_in_userns Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:40 +0100
  [PATCH v2 09/18] fs: Refuse uid/gid changes which don't map into s_user_ns Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:40 +0100
  [PATCH v2 06/18] Smack: Handle labels consistently in untrusted mounts Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:40 +0100
  [PATCH v2 01/18] block_dev: Support checking inode permissions in lookup_bdev() Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:40 +0100
  [PATCH v2 02/18] block_dev: Check permissions towards block device inode when mounting Seth Forshee <seth.forshee@canonical.com> - 2015-12-07 22:40 +0100

csiph-web