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From:   =?UTF-8?q?Michael=20Wei=C3=9F?= <michael.weiss@aisec.fraunhofer.de>
To:     michael.weiss@aisec.fraunhofer.de
Cc:     Song Liu <song@kernel.org>, Alasdair Kergon <agk@redhat.com>,
        Mike Snitzer <snitzer@redhat.com>, dm-devel@redhat.com,
        Paul Moore <paul@paul-moore.com>,
        Eric Paris <eparis@redhat.com>, linux-kernel@vger.kernel.org,
        linux-raid@vger.kernel.org, linux-audit@redhat.com
Subject: [PATCH 3/3] dm crypt: log aead integrity violations to audit subsystem
Date:   Thu, 12 Aug 2021 16:57:44 +0200
Message-Id: <20210812145748.4460-4-michael.weiss@aisec.fraunhofer.de>
In-Reply-To: <20210812145748.4460-1-michael.weiss@aisec.fraunhofer.de>
References: <20210812145748.4460-1-michael.weiss@aisec.fraunhofer.de>
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Precedence: bulk

Since dm-crypt target can be stacked on dm-integrity targets to
provide authenticated encryption, integrity violations are recognized
here during aead computation. We use the dm-audit submodule to
signal those events to user space, too.

The construction and destruction of crypt device mappings are also
logged as audit events.

Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
---
 drivers/md/dm-crypt.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 50f4cbd600d5..343aef4dcf5e 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -41,6 +41,8 @@
 
 #include <linux/device-mapper.h>
 
+#include "dm-audit.h"
+
 #define DM_MSG_PREFIX "crypt"
 
 /*
@@ -1122,6 +1124,7 @@ static bool crypt_integrity_hmac(struct crypt_config *cc)
 	return crypt_integrity_aead(cc) && cc->key_mac_size;
 }
 
+
 /* Get sg containing data */
 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
 					     struct scatterlist *sg)
@@ -1362,8 +1365,12 @@ static int crypt_convert_block_aead(struct crypt_config *cc,
 
 	if (r == -EBADMSG) {
 		char b[BDEVNAME_SIZE];
-		DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b),
-			    (unsigned long long)le64_to_cpu(*sector));
+		sector_t s = le64_to_cpu(*sector);
+
+		DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu",
+			    bio_devname(ctx->bio_in, b), s);
+		dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
+				 ctx->bio_in, s, 0);
 	}
 
 	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
@@ -2173,8 +2180,12 @@ static void kcryptd_async_done(struct crypto_async_request *async_req,
 
 	if (error == -EBADMSG) {
 		char b[BDEVNAME_SIZE];
-		DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b),
-			    (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
+		sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
+
+		DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu",
+			    bio_devname(ctx->bio_in, b), s);
+		dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
+				 ctx->bio_in, s, 0);
 		io->error = BLK_STS_PROTECTION;
 	} else if (error < 0)
 		io->error = BLK_STS_IOERR;
@@ -2729,6 +2740,8 @@ static void crypt_dtr(struct dm_target *ti)
 	dm_crypt_clients_n--;
 	crypt_calculate_pages_per_client();
 	spin_unlock(&dm_crypt_clients_lock);
+
+	dm_audit_log_target(DM_MSG_PREFIX, "dtr", ti, 1);
 }
 
 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
@@ -3357,9 +3370,11 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	ti->num_flush_bios = 1;
 	ti->limit_swap_bios = true;
 
+	dm_audit_log_target(DM_MSG_PREFIX, "ctr", ti, 1);
 	return 0;
 
 bad:
+	dm_audit_log_target(DM_MSG_PREFIX, "ctr", ti, 0);
 	crypt_dtr(ti);
 	return ret;
 }
-- 
2.20.1