static int process_measurement(struct file *file, const unsigned char *filename,
int mask, int function)
{
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;
int rc;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
iint = ima_iint_find_insert_get(inode);
if (!iint)
return -ENOMEM;
mutex_lock(&iint->mutex);
rc = ima_must_measure(iint, inode, mask, function);
if (rc != 0)
goto out;
rc = ima_collect_measurement(iint, file);
if (!rc)
ima_store_measurement(iint, file, filename);
out:
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
return rc;
}
/*
* ima_rdwr_violation_check
*
* Only invalidate the PCR for measured files:
* - Opening a file for write when already open for read,
* results in a time of measure, time of use (ToMToU) error.
* - Opening a file for read when already open for write,
* could result in a file measurement error.
*
*/
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;
bool send_tomtou = false, send_writers = false;
if (!S_ISREG(inode->i_mode) || !ima_initialized)
return;
mutex_lock(&inode->i_mutex); /* file metadata: permissions, xattr */
if (mode & FMODE_WRITE) {
if (atomic_read(&inode->i_readcount) && IS_IMA(inode))
send_tomtou = true;
goto out;
}
rc = ima_must_measure(inode, MAY_READ, FILE_CHECK);
if (rc < 0)
goto out;
if (atomic_read(&inode->i_writecount) > 0)
send_writers = true;
out:
mutex_unlock(&inode->i_mutex);
if (send_tomtou)
ima_add_violation(inode, dentry->d_name.name, "invalid_pcr",
"ToMToU");
if (send_writers)
ima_add_violation(inode, dentry->d_name.name, "invalid_pcr",
"open_writers");
}
static int process_measurement(struct file *file, const unsigned char *filename,
int mask, int function)
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint;
int rc = 0;
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;
}
mutex_lock(&iint->mutex);
rc = iint->flags & IMA_MEASURED ? 1 : 0;
if (rc != 0)
goto out;
rc = ima_collect_measurement(iint, file);
if (!rc)
ima_store_measurement(iint, file, filename);
out:
mutex_unlock(&iint->mutex);
return rc;
}
/**
* ima_path_check - based on policy, collect/store measurement.
* @path: contains a pointer to the path to be measured
* @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE
*
* Measure the file being open for readonly, based on the
* ima_must_measure() policy decision.
*
* Keep read/write counters for all files, but only
* invalidate the PCR for measured files:
* - Opening a file for write when already open for read,
* results in a time of measure, time of use (ToMToU) error.
* - Opening a file for read when already open for write,
* could result in a file measurement error.
*
* Always return 0 and audit dentry_open failures.
* (Return code will be based upon measurement appraisal.)
*/
int ima_path_check(struct path *path, int mask, int update_counts)
{
struct inode *inode = path->dentry->d_inode;
struct ima_iint_cache *iint;
struct file *file = NULL;
int rc;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
iint = ima_iint_find_insert_get(inode);
if (!iint)
return 0;
mutex_lock(&iint->mutex);
if (update_counts)
ima_update_counts(iint, mask);
rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK);
if (rc < 0)
goto out;
if ((mask & MAY_WRITE) || (mask == 0))
ima_read_write_check(TOMTOU, iint, inode,
path->dentry->d_name.name);
if ((mask & (MAY_WRITE | MAY_READ | MAY_EXEC)) != MAY_READ)
goto out;
ima_read_write_check(OPEN_WRITERS, iint, inode,
path->dentry->d_name.name);
if (!(iint->flags & IMA_MEASURED)) {
struct dentry *dentry = dget(path->dentry);
struct vfsmount *mnt = mntget(path->mnt);
file = dentry_open(dentry, mnt, O_RDONLY | O_LARGEFILE,
current_cred());
if (IS_ERR(file)) {
int audit_info = 0;
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
dentry->d_name.name,
"add_measurement",
"dentry_open failed",
1, audit_info);
file = NULL;
goto out;
}
rc = get_path_measurement(iint, file, dentry->d_name.name);
}
out:
mutex_unlock(&iint->mutex);
if (file)
fput(file);
kref_put(&iint->refcount, iint_free);
return 0;
}
/*
* ima_rdwr_violation_check
*
* Only invalidate the PCR for measured files:
* - Opening a file for write when already open for read,
* results in a time of measure, time of use (ToMToU) error.
* - Opening a file for read when already open for write,
* could result in a file measurement error.
*
*/
static void ima_rdwr_violation_check(struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = file_inode(file);
fmode_t mode = file->f_mode;
int must_measure;
bool send_tomtou = false, send_writers = false;
char *pathbuf = NULL;
const char *pathname;
if (!S_ISREG(inode->i_mode) || !ima_initialized)
return;
mutex_lock(&inode->i_mutex); /* file metadata: permissions, xattr */
if (mode & FMODE_WRITE) {
if (atomic_read(&inode->i_readcount) && IS_IMA(inode))
send_tomtou = true;
goto out;
}
must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK);
if (!must_measure)
goto out;
if (atomic_read(&inode->i_writecount) > 0)
send_writers = true;
out:
mutex_unlock(&inode->i_mutex);
if (!send_tomtou && !send_writers)
return;
pathname = ima_d_path(&file->f_path, &pathbuf);
if (!pathname || strlen(pathname) > IMA_EVENT_NAME_LEN_MAX)
pathname = dentry->d_name.name;
if (send_tomtou)
ima_add_violation(file, pathname, "invalid_pcr", "ToMToU");
if (send_writers)
ima_add_violation(file, pathname,
"invalid_pcr", "open_writers");
kfree(pathbuf);
}
/*
* ima_rdwr_violation_check
*
* Only invalidate the PCR for measured files:
* - Opening a file for write when already open for read,
* results in a time of measure, time of use (ToMToU) error.
* - Opening a file for read when already open for write,
* could result in a file measurement error.
*
*/
static void ima_rdwr_violation_check(struct file *file)
{
struct inode *inode = file_inode(file);
fmode_t mode = file->f_mode;
bool send_tomtou = false, send_writers = false;
char *pathbuf = NULL;
const char *pathname;
if (!S_ISREG(inode->i_mode) || !ima_initialized)
return;
if (mode & FMODE_WRITE) {
if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
struct integrity_iint_cache *iint;
iint = integrity_iint_find(inode);
/* IMA_MEASURE is set from reader side */
if (iint && (iint->flags & IMA_MEASURE))
send_tomtou = true;
}
} else {
if ((atomic_read(&inode->i_writecount) > 0) &&
ima_must_measure(inode, MAY_READ, FILE_CHECK))
send_writers = true;
}
if (!send_tomtou && !send_writers)
return;
pathname = ima_d_path(&file->f_path, &pathbuf);
if (send_tomtou)
ima_add_violation(file, pathname, "invalid_pcr", "ToMToU");
if (send_writers)
ima_add_violation(file, pathname,
"invalid_pcr", "open_writers");
kfree(pathbuf);
}
