[PATCH 10/11] ima: Don't ignore errors from crypto_shash_update()

[Roberto Sassu]

Errors returned by crypto_shash_update() are not checked in
ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next
iteration of the loop. This patch adds a check after calling
crypto_shash_update() and returns immediately if the result is not zero.

Cc: stable at vger.kernel.org
Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
---
 security/integrity/ima/ima_crypto.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 220b14920c37..47897fbae6c6 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -829,6 +829,8 @@ static int ima_calc_boot_aggregate_tfm(char *digest, u16 alg_id,
 		/* now accumulate with current aggregate */
 		rc = crypto_shash_update(shash, d.digest,
 					 crypto_shash_digestsize(tfm));
+		if (rc != 0)
+			return rc;
 	}
 	if (!rc)
 		crypto_shash_final(shash, digest);
-- 
2.17.1