diff options
Diffstat (limited to 'security/integrity/ima/ima_main.c')
-rw-r--r-- | security/integrity/ima/ima_main.c | 93 |
1 files changed, 60 insertions, 33 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index be8294915cf..73c9a268253 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); |