ima: prevent buffer overflow in ima_alloc_tfm()

This patch fixes the case where the file's signature/hash xattr contains
an invalid hash algorithm.  Although we can not verify the xattr, we still
need to measure the file.  Use the default IMA hash algorithm.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Dmitry Kasatkin 2014-08-15 13:28:52 +03:00 committed by Mimi Zohar
parent 9a8d289fbc
commit 23c19e2ca7

View File

@ -116,7 +116,10 @@ static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
struct crypto_shash *tfm = ima_shash_tfm;
int rc;
if (algo != ima_hash_algo && algo < HASH_ALGO__LAST) {
if (algo < 0 || algo >= HASH_ALGO__LAST)
algo = ima_hash_algo;
if (algo != ima_hash_algo) {
tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
if (IS_ERR(tfm)) {
rc = PTR_ERR(tfm);