linux-stable/fs/overlayfs
Mimi Zohar 5ff849948c ima: detect changes to the backing overlay file
commit b836c4d29f upstream.

Commit 18b44bc5a6 ("ovl: Always reevaluate the file signature for
IMA") forced signature re-evaulation on every file access.

Instead of always re-evaluating the file's integrity, detect a change
to the backing file, by comparing the cached file metadata with the
backing file's metadata.  Verifying just the i_version has not changed
is insufficient.  In addition save and compare the i_ino and s_dev
as well.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Eric Snowberg <eric.snowberg@oracle.com>
Tested-by: Raul E Rangel <rrangel@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 16:56:29 +00:00
..
Kconfig
Makefile
copy_up.c
dir.c
export.c
file.c
inode.c
namei.c
overlayfs.h
ovl_entry.h
readdir.c
super.c
util.c