[RFC PATCH v4 07/12] dm-verity: add bdev_setsecurity hook for dm-verity signature

Deven Bowers
2020-07-17T23:10:47Z

Add a security hook call to set a security property of a block_device
in dm-verity with the results of a verified, signed root-hash.

Signed-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
---
drivers/md/dm-verity-verify-sig.c | 7 +++++++
include/linux/device-mapper.h | 2 ++
2 files changed, 9 insertions(+)

diff --git a/drivers/md/dm-verity-verify-sig.c b/drivers/md/dm-verity-verify-sig.c
index 27dac8aa2e5a..242e2421d3c8 100644
--- a/drivers/md/dm-verity-verify-sig.c
+++ b/drivers/md/dm-verity-verify-sig.c
@@ -8,7 +8,10 @@
#include <linux/device-mapper.h>
#include <linux/verification.h>
#include <keys/user-type.h>
+#include <linux/security.h>
+#include <linux/list.h>
#include <linux/module.h>
+#include "dm-core.h"
#include "dm-verity.h"
#include "dm-verity-verify-sig.h"

@@ -182,6 +185,10 @@ int verity_verify_root_hash(const struct dm_verity *v)
goto cleanup;

sig_target->passed = true;
+
+ ret = security_bdev_setsecurity(dm_table_get_md(v->ti->table)->bdev,
+ DM_VERITY_SIGNATURE_SEC_NAME,
+ v->sig->sig, v->sig->sig_size);
cleanup:
kfree(root_hash);
return ret;
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 8750f2dc5613..02be0be21d38 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -624,4 +624,6 @@ static inline unsigned long to_bytes(sector_t n)
return (n << SECTOR_SHIFT);
}

+#define DM_VERITY_SIGNATURE_SEC_NAME DM_NAME ".verity-sig"
+
#endif /* _LINUX_DEVICE_MAPPER_H */
--
2.27.0