ima: re-evaluate file integrity on file metadata change

Force a file's integrity to be re-evaluated on file metadata change by
resetting both the IMA and EVM status flags.

Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Stefan Berger 2024-02-23 12:25:10 -05:00 committed by Mimi Zohar
parent a652aa5906
commit cd9b909a11

View File

@ -26,6 +26,7 @@
#include <linux/ima.h>
#include <linux/fs.h>
#include <linux/iversion.h>
#include <linux/evm.h>
#include "ima.h"
@ -211,6 +212,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
struct inode *real_inode, *inode = file_inode(file);
struct ima_iint_cache *iint = NULL;
struct ima_template_desc *template_desc = NULL;
struct inode *metadata_inode;
char *pathbuf = NULL;
char filename[NAME_MAX];
const char *pathname = NULL;
@ -286,7 +288,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
}
/*
* On stacked filesystems, detect and re-evaluate file data changes.
* On stacked filesystems, detect and re-evaluate file data and
* metadata changes.
*/
real_inode = d_real_inode(file_dentry(file));
if (real_inode != inode &&
@ -297,6 +300,15 @@ static int process_measurement(struct file *file, const struct cred *cred,
iint->flags &= ~IMA_DONE_MASK;
iint->measured_pcrs = 0;
}
/*
* Reset the EVM status when metadata changed.
*/
metadata_inode = d_inode(d_real(file_dentry(file),
D_REAL_METADATA));
if (evm_metadata_changed(inode, metadata_inode))
iint->flags &= ~(IMA_APPRAISED |
IMA_APPRAISED_SUBMASK);
}
/* Determine if already appraised/measured based on bitmask