From: Mimi Zohar Date: Mon, 28 Jul 2014 11:59:49 +0000 (-0400) Subject: ima: fix ima_alloc_atfm() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9a8d289fbcb7dfd1fc74959e9930b406e76b2002;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git ima: fix ima_alloc_atfm() The patch 3bcced39ea7d: "ima: use ahash API for file hash calculation" from Feb 26, 2014, leads to the following static checker warning: security/integrity/ima/ima_crypto.c:204 ima_alloc_atfm()          error: buffer overflow 'hash_algo_name' 17 <= 17 Unlike shash tfm memory, which is allocated on initialization, the ahash tfm memory allocation is deferred until needed. This patch fixes the case where ima_ahash_tfm has not yet been allocated and 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. Changelog: - set valid algo before testing tfm - based on Dmitry's comment Reported-by: Dan Carpenter Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin --- diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 0bd732843fe7..2d103dc13d90 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -200,7 +200,10 @@ static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo) struct crypto_ahash *tfm = ima_ahash_tfm; int rc; - if ((algo != ima_hash_algo && algo < HASH_ALGO__LAST) || !tfm) { + if (algo < 0 || algo >= HASH_ALGO__LAST) + algo = ima_hash_algo; + + if (algo != ima_hash_algo || !tfm) { tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0); if (!IS_ERR(tfm)) { if (algo == ima_hash_algo)