ima: Don't ignore errors from crypto_shash_update()

commit 60386b854008adc951c470067f90a2d85b5d520f upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 7b16e54f01c6049286bc8007b788c5ef43aa5b28..2c8fd4e907009ed478cb664658d46c0b457ab874 100644 (file)
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -699,6 +699,8 @@ static int __init ima_calc_boot_aggregate_tfm(char *digest,
                ima_pcrread(i, pcr_i);
                /* now accumulate with current aggregate */
                rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
+               if (rc != 0)
+                       return rc;
        }
        if (!rc)
                crypto_shash_final(shash, digest);