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From:   Deven Bowers <deven.desai@linux.microsoft.com>
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Subject: [RFC PATCH v6 08/11] dm-verity: add bdev_setsecurity hook for root-hash
Date:   Wed, 29 Jul 2020 17:31:10 -0700
Message-Id: <20200730003113.2561644-9-deven.desai@linux.microsoft.com>
In-Reply-To: <20200730003113.2561644-1-deven.desai@linux.microsoft.com>
References: <20200730003113.2561644-1-deven.desai@linux.microsoft.com>
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Add a security hook call to set a security property of a block_device
in dm-verity with the root-hash that was passed to device-mapper.

Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
---
 drivers/md/dm-verity-target.c | 8 ++++++++
 include/linux/device-mapper.h | 1 +
 2 files changed, 9 insertions(+)

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 9970488e67ed..44914668398d 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -16,8 +16,10 @@
 #include "dm-verity.h"
 #include "dm-verity-fec.h"
 #include "dm-verity-verify-sig.h"
+#include "dm-core.h"
 #include <linux/module.h>
 #include <linux/reboot.h>
+#include <linux/security.h>
 
 #define DM_MSG_PREFIX			"verity"
 
@@ -1207,6 +1209,12 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 	ti->per_io_data_size = roundup(ti->per_io_data_size,
 				       __alignof__(struct dm_verity_io));
 
+	r = security_bdev_setsecurity(dm_table_get_md(v->ti->table)->bdev,
+				      DM_VERITY_ROOTHASH_SEC_NAME,
+				      v->root_digest, v->digest_size);
+	if (r)
+		goto bad;
+
 	verity_verify_sig_opts_cleanup(&verify_args);
 
 	return 0;
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index ab6b8eb0a150..e8ef887e4bae 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -626,5 +626,6 @@ static inline unsigned long to_bytes(sector_t n)
 }
 
 #define DM_VERITY_SIGNATURE_SEC_NAME DM_NAME	".verity-sig"
+#define DM_VERITY_ROOTHASH_SEC_NAME DM_NAME	".verity-rh"
 
 #endif	/* _LINUX_DEVICE_MAPPER_H */
-- 
2.27.0