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From: "Mickaël Salaün" <mic@digikod.net>
To: linux-kernel@vger.kernel.org
Cc: "Mickaël Salaün" <mic@digikod.net>,
	"Aleksa Sarai" <cyphar@cyphar.com>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Al Viro" <viro@zeniv.linux.org.uk>,
	"Andy Lutomirski" <luto@kernel.org>,
	"Christian Heimes" <christian@python.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Deven Bowers" <deven.desai@linux.microsoft.com>,
	"Eric Chiang" <ericchiang@google.com>,
	"Florian Weimer" <fweimer@redhat.com>,
	"James Morris" <jmorris@namei.org>, "Jan Kara" <jack@suse.cz>,
	"Jann Horn" <jannh@google.com>,
	"Jonathan Corbet" <corbet@lwn.net>,
	"Kees Cook" <keescook@chromium.org>,
	"Lakshmi Ramasubramanian" <nramas@linux.microsoft.com>,
	"Matthew Garrett" <mjg59@google.com>,
	"Matthew Wilcox" <willy@infradead.org>,
	"Michael Kerrisk" <mtk.manpages@gmail.com>,
	"Mickaël Salaün" <mickael.salaun@ssi.gouv.fr>,
	"Mimi Zohar" <zohar@linux.ibm.com>,
	"Philippe Trébuchet" <philippe.trebuchet@ssi.gouv.fr>,
	"Scott Shell" <scottsh@microsoft.com>,
	"Sean Christopherson" <sean.j.christopherson@intel.com>,
	"Shuah Khan" <shuah@kernel.org>,
	"Steve Dower" <steve.dower@python.org>,
	"Steve Grubb" <sgrubb@redhat.com>,
	"Thibaut Sautereau" <thibaut.sautereau@ssi.gouv.fr>,
	"Vincent Strubel" <vincent.strubel@ssi.gouv.fr>,
	kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
	linux-integrity@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: [PATCH v5 6/6] ima: add policy support for the new file open MAY_OPENEXEC flag
Date: Tue,  5 May 2020 17:31:56 +0200
Message-ID: <20200505153156.925111-7-mic@digikod.net> (raw)
In-Reply-To: <20200505153156.925111-1-mic@digikod.net>

From: Mimi Zohar <zohar@linux.ibm.com>

The kernel has no way of differentiating between a file containing data
or code being opened by an interpreter.  The proposed O_MAYEXEC
openat2(2) flag bridges this gap by defining and enabling the
MAY_OPENEXEC flag.

This patch adds IMA policy support for the new MAY_OPENEXEC flag.

Example:
measure func=FILE_CHECK mask=^MAY_OPENEXEC
appraise func=FILE_CHECK appraise_type=imasig mask=^MAY_OPENEXEC

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Link: https://lore.kernel.org/r/1588167523-7866-3-git-send-email-zohar@linux.ibm.com
---
 Documentation/ABI/testing/ima_policy |  2 +-
 security/integrity/ima/ima_main.c    |  3 ++-
 security/integrity/ima/ima_policy.c  | 15 +++++++++++----
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index cd572912c593..caca46125fe0 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -31,7 +31,7 @@ Description:
 				[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
 				[KEXEC_CMDLINE] [KEY_CHECK]
 			mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
-			       [[^]MAY_EXEC]
+			       [[^]MAY_EXEC] [[^]MAY_OPENEXEC]
 			fsmagic:= hex value
 			fsuuid:= file system UUID (e.g 8bcbe394-4f13-4144-be8e-5aa9ea2ce2f6)
 			uid:= decimal value
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 9d0abedeae77..c80cdaf13626 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -438,7 +438,8 @@ int ima_file_check(struct file *file, int mask)
 
 	security_task_getsecid(current, &secid);
 	return process_measurement(file, current_cred(), secid, NULL, 0,
-				   mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
+				   mask & (MAY_READ | MAY_WRITE |
+					   MAY_EXEC | MAY_OPENEXEC |
 					   MAY_APPEND), FILE_CHECK);
 }
 EXPORT_SYMBOL_GPL(ima_file_check);
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index c334e0dc6083..f54cbc55498d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -406,7 +406,8 @@ static bool ima_match_keyring(struct ima_rule_entry *rule,
  * @cred: a pointer to a credentials structure for user validation
  * @secid: the secid of the task to be validated
  * @func: LIM hook identifier
- * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC |
+ *			    MAY_OPENEXEC)
  * @keyring: keyring name to check in policy for KEY_CHECK func
  *
  * Returns true on rule match, false on failure.
@@ -527,7 +528,8 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
  *        being made
  * @secid: LSM secid of the task to be validated
  * @func: IMA hook identifier
- * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
+ * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC |
+ *			    MAY_OPENEXEC)
  * @pcr: set the pcr to extend
  * @template_desc: the template that should be used for this rule
  * @keyring: the keyring name, if given, to be used to check in the policy.
@@ -1089,6 +1091,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 				entry->mask = MAY_READ;
 			else if (strcmp(from, "MAY_APPEND") == 0)
 				entry->mask = MAY_APPEND;
+			else if (strcmp(from, "MAY_OPENEXEC") == 0)
+				entry->mask = MAY_OPENEXEC;
 			else
 				result = -EINVAL;
 			if (!result)
@@ -1420,14 +1424,15 @@ const char *const func_tokens[] = {
 
 #ifdef	CONFIG_IMA_READ_POLICY
 enum {
-	mask_exec = 0, mask_write, mask_read, mask_append
+	mask_exec = 0, mask_write, mask_read, mask_append, mask_openexec
 };
 
 static const char *const mask_tokens[] = {
 	"^MAY_EXEC",
 	"^MAY_WRITE",
 	"^MAY_READ",
-	"^MAY_APPEND"
+	"^MAY_APPEND",
+	"^MAY_OPENEXEC"
 };
 
 void *ima_policy_start(struct seq_file *m, loff_t *pos)
@@ -1516,6 +1521,8 @@ int ima_policy_show(struct seq_file *m, void *v)
 			seq_printf(m, pt(Opt_mask), mt(mask_read) + offset);
 		if (entry->mask & MAY_APPEND)
 			seq_printf(m, pt(Opt_mask), mt(mask_append) + offset);
+		if (entry->mask & MAY_OPENEXEC)
+			seq_printf(m, pt(Opt_mask), mt(mask_openexec) + offset);
 		seq_puts(m, " ");
 	}
 
-- 
2.26.2


  parent reply index

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-05 15:31 [PATCH v5 0/6] Add support for O_MAYEXEC Mickaël Salaün
2020-05-05 15:31 ` [PATCH v5 1/6] fs: Add support for an O_MAYEXEC flag on openat2(2) Mickaël Salaün
2020-05-12 21:05   ` Kees Cook
2020-05-12 21:40     ` Christian Heimes
2020-05-12 22:56       ` Kees Cook
2020-05-13 10:13     ` Mickaël Salaün
2020-05-05 15:31 ` [PATCH v5 2/6] fs: Add a MAY_EXECMOUNT flag to infer the noexec mount property Mickaël Salaün
2020-05-12 21:09   ` Kees Cook
2020-05-14  8:14     ` Lev R. Oshvang .
2020-05-14 15:48       ` Kees Cook
2020-05-17 16:57         ` Lev R. Oshvang .
2020-05-05 15:31 ` [PATCH v5 3/6] fs: Enable to enforce noexec mounts or file exec through O_MAYEXEC Mickaël Salaün
2020-05-05 15:44   ` Randy Dunlap
2020-05-05 16:55     ` Mickaël Salaün
2020-05-05 17:40       ` Randy Dunlap
2020-05-12 21:48   ` Kees Cook
2020-05-13 11:09     ` Mickaël Salaün
2020-05-13 15:37   ` Stephen Smalley
2020-05-13 23:27     ` Kees Cook
2020-05-14  3:05       ` Kees Cook
2020-05-14 10:12         ` David Laight
2020-05-14 12:22         ` Stephen Smalley
2020-05-14 14:41           ` Kees Cook
2020-05-14 15:52             ` Stephen Smalley
2020-05-14 15:45           ` Kees Cook
2020-05-14 16:10             ` Stephen Smalley
2020-05-14 19:16               ` Mickaël Salaün
2020-05-15  0:58                 ` Tetsuo Handa
2020-05-15  8:01                 ` How about just O_EXEC? (was Re: [PATCH v5 3/6] fs: Enable to enforce noexec mounts or file exec through O_MAYEXEC) Kees Cook
2020-05-15  8:43                   ` Florian Weimer
2020-05-15 14:37                     ` Kees Cook
2020-05-15 14:43                       ` Florian Weimer
2020-05-15 15:50                         ` Kees Cook
2020-05-18  7:26                           ` Florian Weimer
2020-05-19  2:23                           ` Aleksa Sarai
2020-05-19 10:13                             ` Mickaël Salaün
2020-05-15 11:04                   ` Mickaël Salaün
2020-05-15 15:46                     ` Kees Cook
2020-05-15 18:24                       ` Mickaël Salaün
2020-05-14 19:21       ` [PATCH v5 3/6] fs: Enable to enforce noexec mounts or file exec through O_MAYEXEC Mickaël Salaün
2020-05-05 15:31 ` [PATCH v5 4/6] selftest/openat2: Add tests for O_MAYEXEC enforcing Mickaël Salaün
2020-05-12 21:57   ` Kees Cook
2020-05-13 11:18     ` Mickaël Salaün
2020-05-05 15:31 ` [PATCH v5 5/6] doc: Add documentation for the fs.open_mayexec_enforce sysctl Mickaël Salaün
2020-05-12 22:00   ` Kees Cook
2020-05-13 11:20     ` Mickaël Salaün
2020-05-05 15:31 ` Mickaël Salaün [this message]
2020-05-05 15:36 ` [PATCH v5 0/6] Add support for O_MAYEXEC Mickaël Salaün
2020-05-06 13:58   ` Lev R. Oshvang .
2020-05-06 15:41     ` Aleksa Sarai
2020-05-07  8:30     ` Mickaël Salaün
2020-05-07  8:05 ` David Laight
2020-05-07  8:36   ` Mickaël Salaün
2020-05-07  9:00     ` David Laight
2020-05-07  9:30       ` Mickaël Salaün
2020-05-07  9:44         ` David Laight
2020-05-07 13:38           ` Mickaël Salaün
2020-05-08  7:15             ` Lev R. Oshvang .
2020-05-08 14:01               ` Mimi Zohar

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