diff options
| -rw-r--r-- | security/integrity/iint.c | 2 | ||||
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 27 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 70 | ||||
| -rw-r--r-- | security/integrity/integrity.h | 18 |
4 files changed, 77 insertions, 40 deletions
diff --git a/security/integrity/iint.c b/security/integrity/iint.c index c84e05866052..d726ba23a178 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -155,12 +155,14 @@ static void init_once(void *foo) memset(iint, 0, sizeof(*iint)); iint->version = 0; iint->flags = 0UL; + iint->atomic_flags = 0; iint->ima_file_status = INTEGRITY_UNKNOWN; iint->ima_mmap_status = INTEGRITY_UNKNOWN; iint->ima_bprm_status = INTEGRITY_UNKNOWN; iint->ima_read_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; iint->measured_pcrs = 0; + mutex_init(&iint->mutex); } static int __init integrity_iintcache_init(void) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 084c19e45668..ea1245606a14 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -251,6 +251,7 @@ int ima_appraise_measurement(enum ima_hooks func, status = INTEGRITY_FAIL; break; } + clear_bit(IMA_DIGSIG, &iint->atomic_flags); if (xattr_len - sizeof(xattr_value->type) - hash_start >= iint->ima_hash->length) /* xattr length may be longer. md5 hash in previous @@ -269,7 +270,7 @@ int ima_appraise_measurement(enum ima_hooks func, status = INTEGRITY_PASS; break; case EVM_IMA_XATTR_DIGSIG: - iint->flags |= IMA_DIGSIG; + set_bit(IMA_DIGSIG, &iint->atomic_flags); rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA, (const char *)xattr_value, rc, iint->ima_hash->digest, @@ -320,7 +321,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) int rc = 0; /* do not collect and update hash for digital signatures */ - if (iint->flags & IMA_DIGSIG) + if (test_bit(IMA_DIGSIG, &iint->atomic_flags)) return; if (iint->ima_file_status != INTEGRITY_PASS) @@ -330,7 +331,9 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) if (rc < 0) return; + inode_lock(file_inode(file)); ima_fix_xattr(dentry, iint); + inode_unlock(file_inode(file)); } /** @@ -353,16 +356,14 @@ void ima_inode_post_setattr(struct dentry *dentry) return; must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR); + if (!must_appraise) + __vfs_removexattr(dentry, XATTR_NAME_IMA); iint = integrity_iint_find(inode); if (iint) { - iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | - IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | - IMA_ACTION_RULE_FLAGS); - if (must_appraise) - iint->flags |= IMA_APPRAISE; + set_bit(IMA_CHANGE_ATTR, &iint->atomic_flags); + if (!must_appraise) + clear_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); } - if (!must_appraise) - __vfs_removexattr(dentry, XATTR_NAME_IMA); } /* @@ -391,12 +392,12 @@ static void ima_reset_appraise_flags(struct inode *inode, int digsig) iint = integrity_iint_find(inode); if (!iint) return; - - iint->flags &= ~IMA_DONE_MASK; iint->measured_pcrs = 0; + set_bit(IMA_CHANGE_XATTR, &iint->atomic_flags); if (digsig) - iint->flags |= IMA_DIGSIG; - return; + set_bit(IMA_DIGSIG, &iint->atomic_flags); + else + clear_bit(IMA_DIGSIG, &iint->atomic_flags); } int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 770654694efc..edf4e0717494 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -96,10 +96,13 @@ static void ima_rdwr_violation_check(struct file *file, if (!iint) iint = integrity_iint_find(inode); /* IMA_MEASURE is set from reader side */ - if (iint && (iint->flags & IMA_MEASURE)) + if (iint && test_bit(IMA_MUST_MEASURE, + &iint->atomic_flags)) send_tomtou = true; } } else { + if (must_measure) + set_bit(IMA_MUST_MEASURE, &iint->atomic_flags); if ((atomic_read(&inode->i_writecount) > 0) && must_measure) send_writers = true; } @@ -121,21 +124,24 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint, struct inode *inode, struct file *file) { fmode_t mode = file->f_mode; + bool update; if (!(mode & FMODE_WRITE)) return; - inode_lock(inode); + mutex_lock(&iint->mutex); if (atomic_read(&inode->i_writecount) == 1) { + update = test_and_clear_bit(IMA_UPDATE_XATTR, + &iint->atomic_flags); if ((iint->version != inode->i_version) || (iint->flags & IMA_NEW_FILE)) { iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); iint->measured_pcrs = 0; - if (iint->flags & IMA_APPRAISE) + if (update) ima_update_xattr(iint, file); } } - inode_unlock(inode); + mutex_unlock(&iint->mutex); } /** @@ -168,7 +174,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size, char *pathbuf = NULL; char filename[NAME_MAX]; const char *pathname = NULL; - int rc = -ENOMEM, action, must_appraise; + int rc = 0, action, must_appraise = 0; int pcr = CONFIG_IMA_MEASURE_PCR_IDX; struct evm_ima_xattr_data *xattr_value = NULL; int xattr_len = 0; @@ -199,17 +205,31 @@ static int process_measurement(struct file *file, char *buf, loff_t size, if (action) { iint = integrity_inode_get(inode); if (!iint) - goto out; + rc = -ENOMEM; } - if (violation_check) { + if (!rc && violation_check) ima_rdwr_violation_check(file, iint, action & IMA_MEASURE, &pathbuf, &pathname); - if (!action) { - rc = 0; - goto out_free; - } - } + + inode_unlock(inode); + + if (rc) + goto out; + if (!action) + goto out; + + mutex_lock(&iint->mutex); + + if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags)) + /* reset appraisal flags if ima_inode_post_setattr was called */ + iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | + 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 */ + iint->flags &= ~IMA_DONE_MASK; /* Determine if already appraised/measured based on bitmask * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED, @@ -227,7 +247,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size, if (!action) { if (must_appraise) rc = ima_get_cache_status(iint, func); - goto out_digsig; + goto out_locked; } template_desc = ima_template_desc_current(); @@ -240,7 +260,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size, rc = ima_collect_measurement(iint, file, buf, size, hash_algo); if (rc != 0 && rc != -EBADF && rc != -EINVAL) - goto out_digsig; + goto out_locked; if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */ pathname = ima_d_path(&file->f_path, &pathbuf, filename); @@ -248,26 +268,32 @@ static int process_measurement(struct file *file, char *buf, loff_t size, if (action & IMA_MEASURE) ima_store_measurement(iint, file, pathname, xattr_value, xattr_len, pcr); - if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) + if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) { + inode_lock(inode); rc = ima_appraise_measurement(func, iint, file, pathname, xattr_value, xattr_len, opened); + inode_unlock(inode); + } if (action & IMA_AUDIT) ima_audit_measurement(iint, pathname); if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO)) rc = 0; -out_digsig: - if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG) && +out_locked: + if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) && !(iint->flags & IMA_NEW_FILE)) rc = -EACCES; + mutex_unlock(&iint->mutex); kfree(xattr_value); -out_free: +out: if (pathbuf) __putname(pathbuf); -out: - inode_unlock(inode); - if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE)) - return -EACCES; + if (must_appraise) { + if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; + if (file->f_mode & FMODE_WRITE) + set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); + } return 0; } diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index e324bf98c856..c64ea8f88f66 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -29,11 +29,10 @@ /* iint cache flags */ #define IMA_ACTION_FLAGS 0xff000000 #define IMA_ACTION_RULE_FLAGS 0x06000000 -#define IMA_DIGSIG 0x01000000 -#define IMA_DIGSIG_REQUIRED 0x02000000 -#define IMA_PERMIT_DIRECTIO 0x04000000 -#define IMA_NEW_FILE 0x08000000 -#define EVM_IMMUTABLE_DIGSIG 0x10000000 +#define IMA_DIGSIG_REQUIRED 0x01000000 +#define IMA_PERMIT_DIRECTIO 0x02000000 +#define IMA_NEW_FILE 0x04000000 +#define EVM_IMMUTABLE_DIGSIG 0x08000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_APPRAISE_SUBMASK) @@ -54,6 +53,13 @@ #define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \ IMA_BPRM_APPRAISED | IMA_READ_APPRAISED) +/* iint cache atomic_flags */ +#define IMA_CHANGE_XATTR 0 +#define IMA_UPDATE_XATTR 1 +#define IMA_CHANGE_ATTR 2 +#define IMA_DIGSIG 3 +#define IMA_MUST_MEASURE 4 + enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, EVM_XATTR_HMAC, @@ -102,10 +108,12 @@ struct signature_v2_hdr { /* integrity data associated with an inode */ struct integrity_iint_cache { struct rb_node rb_node; /* rooted in integrity_iint_tree */ + struct mutex mutex; /* protects: version, flags, digest */ struct inode *inode; /* back pointer to inode in question */ u64 version; /* track inode changes */ unsigned long flags; unsigned long measured_pcrs; + unsigned long atomic_flags; enum integrity_status ima_file_status:4; enum integrity_status ima_mmap_status:4; enum integrity_status ima_bprm_status:4; |