/* * ima_counts_put - decrement file counts * * File counts are incremented in ima_path_check. On file open * error, such as ETXTBSY, decrement the counts to prevent * unnecessary imbalance messages. */ void ima_counts_put(struct path *path, int mask) { struct inode *inode = path->dentry->d_inode; struct ima_iint_cache *iint; /* The inode may already have been freed, freeing the iint * with it. Verify the inode is not NULL before dereferencing * it. */ if (!ima_initialized || !inode || !S_ISREG(inode->i_mode)) return; iint = ima_iint_find_insert_get(inode); if (!iint) return; mutex_lock(&iint->mutex); iint->opencount--; if ((mask & MAY_WRITE) || (mask == 0)) iint->writecount--; else if (mask & (MAY_READ | MAY_EXEC)) iint->readcount--; mutex_unlock(&iint->mutex); kref_put(&iint->refcount, iint_free); }
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_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_counts_get - increment file counts * * - for IPC shm and shmat file. * - for nfsd exported files. * * Increment the counts for these files to prevent unnecessary * imbalance messages. */ void ima_counts_get(struct file *file) { struct inode *inode = file->f_dentry->d_inode; struct ima_iint_cache *iint; if (!ima_initialized || !S_ISREG(inode->i_mode)) return; iint = ima_iint_find_insert_get(inode); if (!iint) return; mutex_lock(&iint->mutex); iint->opencount++; if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) iint->readcount++; if (file->f_mode & FMODE_WRITE) iint->writecount++; mutex_unlock(&iint->mutex); }
/* * ima_counts_put - decrement file counts * * File counts are incremented in ima_path_check. On file open * error, such as ETXTBSY, decrement the counts to prevent * unnecessary imbalance messages. */ void ima_counts_put(struct path *path, int mask) { struct inode *inode = path->dentry->d_inode; struct ima_iint_cache *iint; if (!ima_initialized || !S_ISREG(inode->i_mode)) return; iint = ima_iint_find_insert_get(inode); if (!iint) return; mutex_lock(&iint->mutex); iint->opencount--; if ((mask & MAY_WRITE) || (mask == 0)) iint->writecount--; else if (mask & (MAY_READ | MAY_EXEC)) iint->readcount--; mutex_unlock(&iint->mutex); }