On filesystems, such as fuse or remote filesystems, that we can not
detect or rely on the filesystem to tell us when a file has changed,
always re-measure, re-appraise, and/or re-audit the file.
Signed-of-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
---
Hi Miklos,
Was something like this what you had in mind?
Mimi
---
security/integrity/ima/ima_main.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 6d78cb26784d..a428bd75232e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -170,6 +170,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
int mask, enum ima_hooks func, int opened)
{
struct inode *inode = file_inode(file);
+ struct dentry *dentry = file_dentry(file);
struct integrity_iint_cache *iint = NULL;
struct ima_template_desc *template_desc;
char *pathbuf = NULL;
@@ -228,9 +229,16 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
IMA_ACTION_FLAGS);
- if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags))
- /* reset all flags if ima_inode_setxattr was called */
+ /*
+ * Re-measure, re-appraise, and/or re-audit a file, if the security
+ * xattrs changed or if the file is on an untrusted file system
+ * (eg. FUSE, remote filesystems).
+ */
+ if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags) ||
+ (dentry->d_op && dentry->d_op->d_revalidate)) {
iint->flags &= ~IMA_DONE_MASK;
+ iint->measured_pcrs = 0;
+ }
/* Determine if already appraised/measured based on bitmask
* (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
--
2.7.5
