Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753133AbaFWIex (ORCPT ); Mon, 23 Jun 2014 04:34:53 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:55650 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752695AbaFWIca (ORCPT ); Mon, 23 Jun 2014 04:32:30 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Mimi Zohar , Jiri Slaby Subject: [PATCH 3.12 077/111] ima: audit log files opened with O_DIRECT flag Date: Mon, 23 Jun 2014 10:31:52 +0200 Message-Id: X-Mailer: git-send-email 2.0.0 In-Reply-To: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> References: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mimi Zohar 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit f9b2a735bdddf836214b5dca74f6ca7712e5a08c upstream. Files are measured or appraised based on the IMA policy. When a file, in policy, is opened with the O_DIRECT flag, a deadlock occurs. The first attempt at resolving this lockdep temporarily removed the O_DIRECT flag and restored it, after calculating the hash. The second attempt introduced the O_DIRECT_HAVELOCK flag. Based on this flag, do_blockdev_direct_IO() would skip taking the i_mutex a second time. The third attempt, by Dmitry Kasatkin, resolves the i_mutex locking issue, by re-introducing the IMA mutex, but uncovered another problem. Reading a file with O_DIRECT flag set, writes directly to userspace pages. A second patch allocates a user-space like memory. This works for all IMA hooks, except ima_file_free(), which is called on __fput() to recalculate the file hash. Until this last issue is addressed, do not 'collect' the measurement for measuring, appraising, or auditing files opened with the O_DIRECT flag set. Based on policy, permit or deny file access. This patch defines a new IMA policy rule option named 'permit_directio'. Policy rules could be defined, based on LSM or other criteria, to permit specific applications to open files with the O_DIRECT flag set. Changelog v1: - permit or deny file access based IMA policy rules Signed-off-by: Mimi Zohar Acked-by: Dmitry Kasatkin Signed-off-by: Jiri Slaby --- Documentation/ABI/testing/ima_policy | 2 +- security/integrity/ima/ima_api.c | 9 ++++++++- security/integrity/ima/ima_main.c | 5 ++++- security/integrity/ima/ima_policy.c | 6 +++++- security/integrity/integrity.h | 1 + 5 files changed, 19 insertions(+), 4 deletions(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index f1c5cc9d17a8..4c3efe434806 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -23,7 +23,7 @@ Description: [fowner]] lsm: [[subj_user=] [subj_role=] [subj_type=] [obj_user=] [obj_role=] [obj_type=]] - option: [[appraise_type=]] + option: [[appraise_type=]] [permit_directio] base: func:= [BPRM_CHECK][MMAP_CHECK][FILE_CHECK][MODULE_CHECK] mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC] diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 1c03e8f1e0e1..4e1529e3a53d 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -140,6 +140,7 @@ int ima_must_measure(struct inode *inode, int mask, int function) int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file) { + const char *audit_cause = "failed"; struct inode *inode = file_inode(file); const char *filename = file->f_dentry->d_name.name; int result = 0; @@ -147,6 +148,11 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, if (!(iint->flags & IMA_COLLECTED)) { u64 i_version = file_inode(file)->i_version; + if (file->f_flags & O_DIRECT) { + audit_cause = "failed(directio)"; + result = -EACCES; + goto out; + } iint->ima_xattr.type = IMA_XATTR_DIGEST; result = ima_calc_file_hash(file, iint->ima_xattr.digest); if (!result) { @@ -154,9 +160,10 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, iint->flags |= IMA_COLLECTED; } } +out: if (result) integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, - filename, "collect_data", "failed", + filename, "collect_data", audit_cause, result, 0); return result; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index e9508d5bbfcf..03fb126d215a 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -186,8 +186,11 @@ static int process_measurement(struct file *file, const char *filename, } rc = ima_collect_measurement(iint, file); - if (rc != 0) + if (rc != 0) { + if (file->f_flags & O_DIRECT) + rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES; goto out_digsig; + } pathname = !filename ? ima_d_path(&file->f_path, &pathbuf) : filename; if (!pathname) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index a9c3d3cd1990..085c4964be99 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -351,7 +351,7 @@ enum { Opt_obj_user, Opt_obj_role, Opt_obj_type, Opt_subj_user, Opt_subj_role, Opt_subj_type, Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner, - Opt_appraise_type, Opt_fsuuid + Opt_appraise_type, Opt_fsuuid, Opt_permit_directio }; static match_table_t policy_tokens = { @@ -373,6 +373,7 @@ static match_table_t policy_tokens = { {Opt_uid, "uid=%s"}, {Opt_fowner, "fowner=%s"}, {Opt_appraise_type, "appraise_type=%s"}, + {Opt_permit_directio, "permit_directio"}, {Opt_err, NULL} }; @@ -621,6 +622,9 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else result = -EINVAL; break; + case Opt_permit_directio: + entry->flags |= IMA_PERMIT_DIRECTIO; + break; case Opt_err: ima_log_string(ab, "UNKNOWN", p); result = -EINVAL; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index c42fb7a70dee..ecbb6f20f46a 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -30,6 +30,7 @@ #define IMA_ACTION_FLAGS 0xff000000 #define IMA_DIGSIG 0x01000000 #define IMA_DIGSIG_REQUIRED 0x02000000 +#define IMA_PERMIT_DIRECTIO 0x04000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_APPRAISE_SUBMASK) -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/