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-rw-r--r--security/integrity/ima/ima_main.c93
1 files changed, 60 insertions, 33 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index be8294915cf7..73c9a268253e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -22,12 +22,19 @@
#include <linux/mount.h>
#include <linux/mman.h>
#include <linux/slab.h>
+#include <linux/xattr.h>
#include <linux/ima.h>
#include "ima.h"
int ima_initialized;
+#ifdef CONFIG_IMA_APPRAISE
+int ima_appraise = IMA_APPRAISE_ENFORCE;
+#else
+int ima_appraise;
+#endif
+
char *ima_hash = "sha1";
static int __init hash_setup(char *str)
{
@@ -52,7 +59,7 @@ static void ima_rdwr_violation_check(struct file *file)
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
fmode_t mode = file->f_mode;
- int rc;
+ int must_measure;
bool send_tomtou = false, send_writers = false;
unsigned char *pathname = NULL, *pathbuf = NULL;
@@ -67,8 +74,8 @@ static void ima_rdwr_violation_check(struct file *file)
goto out;
}
- rc = ima_must_measure(inode, MAY_READ, FILE_CHECK);
- if (rc < 0)
+ must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK);
+ if (!must_measure)
goto out;
if (atomic_read(&inode->i_writecount) > 0)
@@ -100,17 +107,21 @@ out:
}
static void ima_check_last_writer(struct integrity_iint_cache *iint,
- struct inode *inode,
- struct file *file)
+ struct inode *inode, struct file *file)
{
fmode_t mode = file->f_mode;
- mutex_lock(&iint->mutex);
- if (mode & FMODE_WRITE &&
- atomic_read(&inode->i_writecount) == 1 &&
- iint->version != inode->i_version)
- iint->flags &= ~IMA_MEASURED;
- mutex_unlock(&iint->mutex);
+ if (!(mode & FMODE_WRITE))
+ return;
+
+ mutex_lock(&inode->i_mutex);
+ if (atomic_read(&inode->i_writecount) == 1 &&
+ iint->version != inode->i_version) {
+ iint->flags &= ~IMA_DONE_MASK;
+ if (iint->flags & IMA_APPRAISE)
+ ima_update_xattr(iint, file);
+ }
+ mutex_unlock(&inode->i_mutex);
}
/**
@@ -140,28 +151,37 @@ static int process_measurement(struct file *file, const unsigned char *filename,
struct inode *inode = file->f_dentry->d_inode;
struct integrity_iint_cache *iint;
unsigned char *pathname = NULL, *pathbuf = NULL;
- int rc = 0;
+ int rc = -ENOMEM, action, must_appraise;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
- rc = ima_must_measure(inode, mask, function);
- if (rc != 0)
- return rc;
-retry:
- iint = integrity_iint_find(inode);
- if (!iint) {
- rc = integrity_inode_alloc(inode);
- if (!rc || rc == -EEXIST)
- goto retry;
- return rc;
- }
+ /* Determine if in appraise/audit/measurement policy,
+ * returns IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT bitmask. */
+ action = ima_get_action(inode, mask, function);
+ if (!action)
+ return 0;
- mutex_lock(&iint->mutex);
+ must_appraise = action & IMA_APPRAISE;
- rc = iint->flags & IMA_MEASURED ? 1 : 0;
- if (rc != 0)
+ mutex_lock(&inode->i_mutex);
+
+ iint = integrity_inode_get(inode);
+ if (!iint)
+ goto out;
+
+ /* Determine if already appraised/measured based on bitmask
+ * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED,
+ * IMA_AUDIT, IMA_AUDITED) */
+ iint->flags |= action;
+ action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
+
+ /* Nothing to do, just return existing appraised status */
+ if (!action) {
+ if (iint->flags & IMA_APPRAISED)
+ rc = iint->ima_status;
goto out;
+ }
rc = ima_collect_measurement(iint, file);
if (rc != 0)
@@ -177,11 +197,18 @@ retry:
pathname = NULL;
}
}
- ima_store_measurement(iint, file, !pathname ? filename : pathname);
+ if (action & IMA_MEASURE)
+ ima_store_measurement(iint, file,
+ !pathname ? filename : pathname);
+ if (action & IMA_APPRAISE)
+ rc = ima_appraise_measurement(iint, file,
+ !pathname ? filename : pathname);
+ if (action & IMA_AUDIT)
+ ima_audit_measurement(iint, !pathname ? filename : pathname);
kfree(pathbuf);
out:
- mutex_unlock(&iint->mutex);
- return rc;
+ mutex_unlock(&inode->i_mutex);
+ return (rc && must_appraise) ? -EACCES : 0;
}
/**
@@ -197,14 +224,14 @@ out:
*/
int ima_file_mmap(struct file *file, unsigned long prot)
{
- int rc;
+ int rc = 0;
if (!file)
return 0;
if (prot & PROT_EXEC)
rc = process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, FILE_MMAP);
- return 0;
+ return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
/**
@@ -228,7 +255,7 @@ int ima_bprm_check(struct linux_binprm *bprm)
(strcmp(bprm->filename, bprm->interp) == 0) ?
bprm->filename : bprm->interp,
MAY_EXEC, BPRM_CHECK);
- return 0;
+ return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
/**
@@ -249,7 +276,7 @@ int ima_file_check(struct file *file, int mask)
rc = process_measurement(file, file->f_dentry->d_name.name,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
FILE_CHECK);
- return 0;
+ return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0;
}
EXPORT_SYMBOL_GPL(ima_file_check);
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