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authorEric W. Biederman <ebiederm@xmission.com>2013-03-22 03:10:15 -0700
committerEric W. Biederman <ebiederm@xmission.com>2013-03-27 07:50:04 -0700
commit90563b198e4c6674c63672fae1923da467215f45 (patch)
treeaa8528c1c23dccbeca409059ec5f5d21ca1318bf /include
parent3151527ee007b73a0ebd296010f1c0454a919c7d (diff)
vfs: Add a mount flag to lock read only bind mounts
When a read-only bind mount is copied from mount namespace in a higher privileged user namespace to a mount namespace in a lesser privileged user namespace, it should not be possible to remove the the read-only restriction. Add a MNT_LOCK_READONLY mount flag to indicate that a mount must remain read-only. CC: stable@vger.kernel.org Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mount.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mount.h b/include/linux/mount.h
index d7029f4a191..73005f9957e 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -47,6 +47,8 @@ struct mnt_namespace;
#define MNT_INTERNAL 0x4000
+#define MNT_LOCK_READONLY 0x400000
+
struct vfsmount {
struct dentry *mnt_root; /* root of the mounted tree */
struct super_block *mnt_sb; /* pointer to superblock */