From: JeongHyeon Lee jhs2.lee@samsung.com
[ Upstream commit 88cd3e6cfac915f50f7aa7b699bdf053afec866e ]
The verification is to support cases where the root hash is not secured by Trusted Boot, UEFI Secureboot or similar technologies.
One of the use cases for this is for dm-verity volumes mounted after boot, the root hash provided during the creation of the dm-verity volume has to be secure and thus in-kernel validation implemented here will be used before we trust the root hash and allow the block device to be created.
The signature being provided for verification must verify the root hash and must be trusted by the builtin keyring for verification to succeed.
The hash is added as a key of type "user" and the description is passed to the kernel so it can look it up and use it for verification.
Adds CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG which can be turned on if root hash verification is needed.
Kernel commandline dm_verity module parameter 'require_signatures' will indicate whether to force root hash signature verification (for all dm verity volumes).
Signed-off-by: Jaskaran Khurana jaskarankhurana@linux.microsoft.com Tested-and-Reviewed-by: Milan Broz gmazyland@gmail.com Signed-off-by: Mike Snitzer snitzer@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/md/dm-verity-target.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 6ec3e97814b1d..ca6acc1b20ae8 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -34,7 +34,7 @@ #define DM_VERITY_OPT_IGN_ZEROES "ignore_zero_blocks" #define DM_VERITY_OPT_AT_MOST_ONCE "check_at_most_once"
-#define DM_VERITY_OPTS_MAX (2 + DM_VERITY_OPTS_FEC) +#define DM_VERITY_OPTS_MAX (3 + DM_VERITY_OPTS_FEC)
static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE;