ima: Don't ignore errors from crypto_shash_update()

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@vger.kernel.org
Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 011c3c7..21989fa 100644 (file)
--- 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;
        }
        /*
         * Extend cumulative digest over TPM registers 8-9, which contain