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From: Richard Guy Briggs <rgb@redhat.com>
To: containers@lists.linux-foundation.org, linux-api@vger.kernel.org,
	Linux-Audit Mailing List <linux-audit@redhat.com>,
	linux-fsdevel@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	netdev@vger.kernel.org, netfilter-devel@vger.kernel.org
Cc: Paul Moore <paul@paul-moore.com>,
	sgrubb@redhat.com, omosnace@redhat.com, dhowells@redhat.com,
	simo@redhat.com, eparis@parisplace.org, serge@hallyn.com,
	ebiederm@xmission.com, nhorman@tuxdriver.com, dwalsh@redhat.com,
	mpatel@redhat.com, Richard Guy Briggs <rgb@redhat.com>
Subject: [PATCH ghak90 V8 16/16] audit: add capcontid to set contid outside init_user_ns
Date: Tue, 31 Dec 2019 14:48:29 -0500
Message-ID: <5941671b6b6b5de28ab2cc80e72f288cf83291d5.1577736799.git.rgb@redhat.com> (raw)
In-Reply-To: <cover.1577736799.git.rgb@redhat.com>
In-Reply-To: <cover.1577736799.git.rgb@redhat.com>

Provide a mechanism similar to CAP_AUDIT_CONTROL to explicitly give a
process in a non-init user namespace the capability to set audit
container identifiers.

Provide /proc/$PID/audit_capcontid interface to capcontid.
Valid values are: 1==enabled, 0==disabled

Report this action in message type AUDIT_SET_CAPCONTID 1022 with fields
opid= capcontid= old-capcontid=

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
 fs/proc/base.c             | 55 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/audit.h      | 14 ++++++++++++
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 35 +++++++++++++++++++++++++++++
 4 files changed, 105 insertions(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 26091800180c..283ef8e006e7 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1360,6 +1360,59 @@ static ssize_t proc_contid_write(struct file *file, const char __user *buf,
 	.write		= proc_contid_write,
 	.llseek		= generic_file_llseek,
 };
+
+static ssize_t proc_capcontid_read(struct file *file, char __user *buf,
+				  size_t count, loff_t *ppos)
+{
+	struct inode *inode = file_inode(file);
+	struct task_struct *task = get_proc_task(inode);
+	ssize_t length;
+	char tmpbuf[TMPBUFLEN];
+
+	if (!task)
+		return -ESRCH;
+	/* if we don't have caps, reject */
+	if (!capable(CAP_AUDIT_CONTROL) && !audit_get_capcontid(current))
+		return -EPERM;
+	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", audit_get_capcontid(task));
+	put_task_struct(task);
+	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}
+
+static ssize_t proc_capcontid_write(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	struct inode *inode = file_inode(file);
+	u32 capcontid;
+	int rv;
+	struct task_struct *task = get_proc_task(inode);
+
+	if (!task)
+		return -ESRCH;
+	if (*ppos != 0) {
+		/* No partial writes. */
+		put_task_struct(task);
+		return -EINVAL;
+	}
+
+	rv = kstrtou32_from_user(buf, count, 10, &capcontid);
+	if (rv < 0) {
+		put_task_struct(task);
+		return rv;
+	}
+
+	rv = audit_set_capcontid(task, capcontid);
+	put_task_struct(task);
+	if (rv < 0)
+		return rv;
+	return count;
+}
+
+static const struct file_operations proc_capcontid_operations = {
+	.read		= proc_capcontid_read,
+	.write		= proc_capcontid_write,
+	.llseek		= generic_file_llseek,
+};
 #endif
 
 #ifdef CONFIG_FAULT_INJECTION
@@ -3121,6 +3174,7 @@ static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
 	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
 	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
 	REG("audit_containerid", S_IWUSR|S_IRUSR, proc_contid_operations),
+	REG("audit_capcontainerid", S_IWUSR|S_IRUSR|S_IRUSR, proc_capcontid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
@@ -3522,6 +3576,7 @@ static int proc_tid_comm_permission(struct inode *inode, int mask)
 	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
 	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
 	REG("audit_containerid", S_IWUSR|S_IRUSR, proc_contid_operations),
+	REG("audit_capcontainerid", S_IWUSR|S_IRUSR|S_IRUSR, proc_capcontid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 28b9c7cd86a6..62c453306c2a 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -116,6 +116,7 @@ struct audit_task_info {
 	kuid_t			loginuid;
 	unsigned int		sessionid;
 	struct audit_contobj	*cont;
+	u32			capcontid;
 #ifdef CONFIG_AUDITSYSCALL
 	struct audit_context	*ctx;
 #endif
@@ -224,6 +225,14 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 	return tsk->audit->sessionid;
 }
 
+static inline u32 audit_get_capcontid(struct task_struct *tsk)
+{
+	if (!tsk->audit)
+		return 0;
+	return tsk->audit->capcontid;
+}
+
+extern int audit_set_capcontid(struct task_struct *tsk, u32 enable);
 extern int audit_set_contid(struct task_struct *tsk, u64 contid);
 
 static inline u64 audit_get_contid(struct task_struct *tsk)
@@ -305,6 +314,11 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 	return AUDIT_SID_UNSET;
 }
 
+static inline u32 audit_get_capcontid(struct task_struct *tsk)
+{
+	return 0;
+}
+
 static inline u64 audit_get_contid(struct task_struct *tsk)
 {
 	return AUDIT_CID_UNSET;
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 2844d78cd7af..01251e6dcec0 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -73,6 +73,7 @@
 #define AUDIT_GET_FEATURE	1019	/* Get which features are enabled */
 #define AUDIT_CONTAINER_OP	1020	/* Define the container id and info */
 #define AUDIT_SIGNAL_INFO2	1021	/* Get info auditd signal sender */
+#define AUDIT_SET_CAPCONTID	1022	/* Set cap_contid of a task */
 
 #define AUDIT_FIRST_USER_MSG	1100	/* Userspace messages mostly uninteresting to kernel */
 #define AUDIT_USER_AVC		1107	/* We filter this differently */
diff --git a/kernel/audit.c b/kernel/audit.c
index 1287f0b63757..1c22dd084ae8 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2698,6 +2698,41 @@ static bool audit_contid_isowner(struct task_struct *tsk)
 	return false;
 }
 
+int audit_set_capcontid(struct task_struct *task, u32 enable)
+{
+	u32 oldcapcontid;
+	int rc = 0;
+	struct audit_buffer *ab;
+
+	if (!task->audit)
+		return -ENOPROTOOPT;
+	oldcapcontid = audit_get_capcontid(task);
+	/* if task is not descendant, block */
+	if (task == current)
+		rc = -EBADSLT;
+	else if (!task_is_descendant(current, task))
+		rc = -EXDEV;
+	else if (current_user_ns() == &init_user_ns) {
+		if (!capable(CAP_AUDIT_CONTROL) && !audit_get_capcontid(current))
+			rc = -EPERM;
+	}
+	if (!rc)
+		task->audit->capcontid = enable;
+
+	if (!audit_enabled)
+		return rc;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_SET_CAPCONTID);
+	if (!ab)
+		return rc;
+
+	audit_log_format(ab,
+			 "opid=%d capcontid=%u old-capcontid=%u",
+			 task_tgid_nr(task), enable, oldcapcontid);
+	audit_log_end(ab);
+	return rc;
+}
+
 /*
  * audit_set_contid - set current task's audit contid
  * @task: target task
-- 
1.8.3.1


  parent reply index

Thread overview: 102+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-31 19:48 [PATCH ghak90 V8 00/16] audit: implement container identifier Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 01/16] audit: collect audit task parameters Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 02/16] audit: add container id Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-01-30 17:53     ` Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 03/16] audit: read container ID of a process Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 04/16] audit: convert to contid list to check for orch/engine ownership Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-02-04 22:51     ` Richard Guy Briggs
2020-02-05 22:40       ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 05/16] audit: log drop of contid on exit of last task Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-02-04 23:02     ` Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 06/16] audit: log container info of syscalls Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 07/16] audit: add contid support for signalling the audit daemon Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-01-23 16:29     ` Richard Guy Briggs
2020-01-23 17:09       ` Paul Moore
2020-01-23 20:04         ` Richard Guy Briggs
2020-01-23 21:35           ` Paul Moore
2020-02-04 23:14             ` Richard Guy Briggs
2020-02-05 22:50               ` Paul Moore
2020-02-12 22:38                 ` Steve Grubb
2020-02-13  0:09                   ` Paul Moore
2020-02-13 21:44                     ` Paul Moore
2020-03-12 19:30                       ` Richard Guy Briggs
2020-03-13 16:29                         ` Paul Moore
2020-03-13 18:59                           ` Richard Guy Briggs
2020-03-18 20:56                             ` Paul Moore
2020-03-18 21:26                               ` Richard Guy Briggs
2020-03-18 21:42                                 ` Paul Moore
2020-03-18 21:55                                   ` Richard Guy Briggs
2020-03-18 22:06                                     ` Paul Moore
2020-03-19 22:02                                       ` Richard Guy Briggs
2020-03-24  0:16                                         ` Paul Moore
2020-03-24 21:01                                           ` Richard Guy Briggs
2020-03-29  3:11                                             ` Paul Moore
2020-03-30 13:47                                               ` Richard Guy Briggs
2020-03-30 14:26                                                 ` Paul Moore
2020-03-30 16:21                                                   ` Richard Guy Briggs
2020-03-30 17:34                                                     ` Paul Moore
2020-03-30 17:49                                                       ` Richard Guy Briggs
2020-03-30 19:55                                                         ` Paul Moore
2020-04-16 20:33                                                           ` Eric W. Biederman
2020-04-16 21:53                                                             ` Paul Moore
2020-04-17 22:23                                                               ` Eric W. Biederman
2020-04-22 17:24                                                                 ` Paul Moore
2020-06-08 18:03                                                                   ` Richard Guy Briggs
2020-06-17 21:33                                                                     ` Paul Moore
2020-06-19 15:22                                                                 ` Richard Guy Briggs
2020-03-12 20:27                     ` Richard Guy Briggs
2020-03-13 16:42                       ` Paul Moore
2020-03-13 16:45                         ` Steve Grubb
2020-03-13 16:49                           ` Paul Moore
2020-03-13 19:23                         ` Richard Guy Briggs
2020-03-18 21:01                           ` Paul Moore
2020-03-18 21:41                             ` Richard Guy Briggs
2020-03-18 21:47                               ` Paul Moore
2020-03-19 21:47                                 ` Richard Guy Briggs
2020-03-20 21:56                                   ` Paul Moore
2020-03-25 12:29                                     ` Richard Guy Briggs
2020-03-29  3:17                                       ` Paul Moore
2020-03-30 15:23                                         ` Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 08/16] audit: add support for non-syscall auxiliary records Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 09/16] audit: add containerid support for user records Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 10/16] audit: add containerid filtering Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 11/16] audit: add support for containerid to network namespaces Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-02-04 23:42     ` Richard Guy Briggs
2020-02-05 22:51       ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 12/16] audit: contid check descendancy and nesting Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2020-01-23 21:02     ` Richard Guy Briggs
2020-01-23 21:47       ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 13/16] audit: track container nesting Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2020-01-30 19:27     ` Richard Guy Briggs
2020-02-05 23:05       ` Paul Moore
2020-02-05 23:50         ` Richard Guy Briggs
2020-02-13 21:49           ` Paul Moore
2020-03-12 20:51             ` Richard Guy Briggs
2020-03-13 16:47               ` Paul Moore
2020-03-14 22:42                 ` Richard Guy Briggs
2020-03-17 18:28                   ` Richard Guy Briggs
2020-03-18 21:08                   ` Paul Moore
2020-01-31 14:50     ` Steve Grubb
2020-02-04 13:19       ` Richard Guy Briggs
2020-02-04 15:47         ` Steve Grubb
2020-02-04 15:52           ` Paul Moore
2020-02-04 18:12             ` Steve Grubb
2020-02-05 22:57               ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 14/16] audit: check contid depth and add limit config param Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 15/16] audit: check contid count per netns and add config param limit Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2019-12-31 19:48 ` Richard Guy Briggs [this message]
2020-01-22 21:29   ` [PATCH ghak90 V8 16/16] audit: add capcontid to set contid outside init_user_ns Paul Moore
2020-02-05  0:39     ` Richard Guy Briggs
2020-02-05 22:56       ` Paul Moore
2020-02-06 12:51         ` Richard Guy Briggs
2020-02-13 21:58           ` Paul Moore
2020-03-12 21:58             ` Richard Guy Briggs

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