From: Darrick J. Wong <djwong@xxxxxxxxxx>
We're about to start adding functionality that uses internal inodes that
are private to XFS. What this means is that userspace should never be
able to access any information about these files, and should not be able
to open these files by handle. Callers are not allowed to link these
files into the directory tree, which should suffice to make these
private inodes actually private.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/xfs_export.c | 2 +-
fs/xfs/xfs_itable.c | 8 ++++++++
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c
index 1064c2342876..b6ba96e0dd75 100644
--- a/fs/xfs/xfs_export.c
+++ b/fs/xfs/xfs_export.c
@@ -146,7 +146,7 @@ xfs_nfs_get_inode(
return ERR_PTR(error);
}
- if (VFS_I(ip)->i_generation != generation) {
+ if (VFS_I(ip)->i_generation != generation || IS_PRIVATE(VFS_I(ip))) {
xfs_irele(ip);
return ERR_PTR(-ESTALE);
}
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index f225413a993c..55b307b2d895 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -86,6 +86,14 @@ xfs_bulkstat_one_int(
vfsuid = i_uid_into_vfsuid(idmap, inode);
vfsgid = i_gid_into_vfsgid(idmap, inode);
+ /* If this is a private inode, don't leak its details to userspace. */
+ if (IS_PRIVATE(inode)) {
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ xfs_irele(ip);
+ error = -EINVAL;
+ goto out_advance;
+ }
+
/* xfs_iget returns the following without needing
* further change.
*/
