2020-06-18 20:41:08

by Roberto Sassu

Subject: [PATCH 10/11] 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: [email protected]
Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider")
Signed-off-by: Roberto Sassu <[email protected]>
---
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

2020-08-24 13:04:06

by Mimi Zohar

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

On Thu, 2020-06-18 at 18:04 +0200, Roberto Sassu wrote:
> 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: [email protected]
> Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider")
> Signed-off-by: Roberto Sassu <[email protected]>

Verification of the boot_aggregate will fail, but yes this should be
fixed. This patch and the next should be moved up front to the
beginning of the patch set.

Reviewed-by: Mimi Zohar <[email protected]>

thanks,

Mimi