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-rw-r--r--drivers/md/Kconfig9
-rw-r--r--drivers/md/Makefile4
-rw-r--r--drivers/md/dm-audit.c84
-rw-r--r--drivers/md/dm-audit.h66
-rw-r--r--include/uapi/linux/audit.h2
5 files changed, 165 insertions, 0 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index f45fb372e51b..1bc4f48e9765 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -642,4 +642,13 @@ config DM_ZONED
If unsure, say N.
+config DM_AUDIT
+ bool "DM audit events"
+ depends on AUDIT
+ help
+ Generate audit events for device-mapper.
+
+ Enables audit logging of several security relevant events in the
+ particular device-mapper targets, especially the integrity target.
+
endif # MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 816945eeed7f..0454b0885b01 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -107,3 +107,7 @@ endif
ifeq ($(CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG),y)
dm-verity-objs += dm-verity-verify-sig.o
endif
+
+ifeq ($(CONFIG_DM_AUDIT),y)
+dm-mod-objs += dm-audit.o
+endif
diff --git a/drivers/md/dm-audit.c b/drivers/md/dm-audit.c
new file mode 100644
index 000000000000..3049dfe67e50
--- /dev/null
+++ b/drivers/md/dm-audit.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Creating audit records for mapped devices.
+ *
+ * Copyright (C) 2021 Fraunhofer AISEC. All rights reserved.
+ *
+ * Authors: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
+ */
+
+#include <linux/audit.h>
+#include <linux/module.h>
+#include <linux/device-mapper.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+
+#include "dm-audit.h"
+#include "dm-core.h"
+
+static struct audit_buffer *dm_audit_log_start(int audit_type,
+ const char *dm_msg_prefix,
+ const char *op)
+{
+ struct audit_buffer *ab;
+
+ if (audit_enabled == AUDIT_OFF)
+ return NULL;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, audit_type);
+ if (unlikely(!ab))
+ return NULL;
+
+ audit_log_format(ab, "module=%s op=%s", dm_msg_prefix, op);
+ return ab;
+}
+
+void dm_audit_log_ti(int audit_type, const char *dm_msg_prefix, const char *op,
+ struct dm_target *ti, int result)
+{
+ struct audit_buffer *ab = NULL;
+ struct mapped_device *md = dm_table_get_md(ti->table);
+ int dev_major = dm_disk(md)->major;
+ int dev_minor = dm_disk(md)->first_minor;
+
+ switch (audit_type) {
+ case AUDIT_DM_CTRL:
+ ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
+ if (unlikely(!ab))
+ return;
+ audit_log_task_info(ab);
+ audit_log_format(ab, " dev=%d:%d error_msg='%s'", dev_major,
+ dev_minor, !result ? ti->error : "success");
+ break;
+ case AUDIT_DM_EVENT:
+ ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
+ if (unlikely(!ab))
+ return;
+ audit_log_format(ab, " dev=%d:%d sector=?", dev_major,
+ dev_minor);
+ break;
+ default: /* unintended use */
+ return;
+ }
+
+ audit_log_format(ab, " res=%d", result);
+ audit_log_end(ab);
+}
+EXPORT_SYMBOL_GPL(dm_audit_log_ti);
+
+void dm_audit_log_bio(const char *dm_msg_prefix, const char *op,
+ struct bio *bio, sector_t sector, int result)
+{
+ struct audit_buffer *ab;
+ int dev_major = MAJOR(bio->bi_bdev->bd_dev);
+ int dev_minor = MINOR(bio->bi_bdev->bd_dev);
+
+ ab = dm_audit_log_start(AUDIT_DM_EVENT, dm_msg_prefix, op);
+ if (unlikely(!ab))
+ return;
+
+ audit_log_format(ab, " dev=%d:%d sector=%llu res=%d",
+ dev_major, dev_minor, sector, result);
+ audit_log_end(ab);
+}
+EXPORT_SYMBOL_GPL(dm_audit_log_bio);
diff --git a/drivers/md/dm-audit.h b/drivers/md/dm-audit.h
new file mode 100644
index 000000000000..2385f2b659be
--- /dev/null
+++ b/drivers/md/dm-audit.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Creating audit records for mapped devices.
+ *
+ * Copyright (C) 2021 Fraunhofer AISEC. All rights reserved.
+ *
+ * Authors: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
+ */
+
+#ifndef DM_AUDIT_H
+#define DM_AUDIT_H
+
+#include <linux/device-mapper.h>
+#include <linux/audit.h>
+
+#ifdef CONFIG_DM_AUDIT
+void dm_audit_log_bio(const char *dm_msg_prefix, const char *op,
+ struct bio *bio, sector_t sector, int result);
+
+/*
+ * dm_audit_log_ti() is not intended to be used directly in dm modules,
+ * the wrapper functions below should be called by dm modules instead.
+ */
+void dm_audit_log_ti(int audit_type, const char *dm_msg_prefix, const char *op,
+ struct dm_target *ti, int result);
+
+static inline void dm_audit_log_ctr(const char *dm_msg_prefix,
+ struct dm_target *ti, int result)
+{
+ dm_audit_log_ti(AUDIT_DM_CTRL, dm_msg_prefix, "ctr", ti, result);
+}
+
+static inline void dm_audit_log_dtr(const char *dm_msg_prefix,
+ struct dm_target *ti, int result)
+{
+ dm_audit_log_ti(AUDIT_DM_CTRL, dm_msg_prefix, "dtr", ti, result);
+}
+
+static inline void dm_audit_log_target(const char *dm_msg_prefix, const char *op,
+ struct dm_target *ti, int result)
+{
+ dm_audit_log_ti(AUDIT_DM_EVENT, dm_msg_prefix, op, ti, result);
+}
+#else
+static inline void dm_audit_log_bio(const char *dm_msg_prefix, const char *op,
+ struct bio *bio, sector_t sector,
+ int result)
+{
+}
+static inline void dm_audit_log_target(const char *dm_msg_prefix,
+ const char *op, struct dm_target *ti,
+ int result)
+{
+}
+static inline void dm_audit_log_ctr(const char *dm_msg_prefix,
+ struct dm_target *ti, int result)
+{
+}
+
+static inline void dm_audit_log_dtr(const char *dm_msg_prefix,
+ struct dm_target *ti, int result)
+{
+}
+#endif
+
+#endif
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index daa481729e9b..809e4c2041b3 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -118,6 +118,8 @@
#define AUDIT_TIME_ADJNTPVAL 1333 /* NTP value adjustment */
#define AUDIT_BPF 1334 /* BPF subsystem */
#define AUDIT_EVENT_LISTENER 1335 /* Task joined multicast read socket */
+#define AUDIT_DM_CTRL 1338 /* Device Mapper target control */
+#define AUDIT_DM_EVENT 1339 /* Device Mapper events */
#define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
#define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */