From: Dinghao Liu <dinghao.liu@zju.edu.cn>
Date: Sun, 10 Jan 2021 08:02:53 +0000 (+0800)
Subject: evm: Fix memleak in init_desc
X-Git-Tag: v5.10.25~981
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=494e9ec12c1b3bf2532b2a518d7206137a01cb6a;p=platform%2Fkernel%2Flinux-rpi.git

evm: Fix memleak in init_desc

[ Upstream commit ccf11dbaa07b328fa469415c362d33459c140a37 ]

tmp_tfm is allocated, but not freed on subsequent kmalloc failure, which
leads to a memory leak.  Free tmp_tfm.

Fixes: d46eb3699502b ("evm: crypto hash replaced by shash")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
[zohar@linux.ibm.com: formatted/reworded patch description]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 168c3b7..a6dd47e 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -73,7 +73,7 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
 {
 	long rc;
 	const char *algo;
-	struct crypto_shash **tfm, *tmp_tfm;
+	struct crypto_shash **tfm, *tmp_tfm = NULL;
 	struct shash_desc *desc;
 
 	if (type == EVM_XATTR_HMAC) {
@@ -118,13 +118,16 @@ unlock:
 alloc:
 	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
 			GFP_KERNEL);
-	if (!desc)
+	if (!desc) {
+		crypto_free_shash(tmp_tfm);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	desc->tfm = *tfm;
 
 	rc = crypto_shash_init(desc);
 	if (rc) {
+		crypto_free_shash(tmp_tfm);
 		kfree(desc);
 		return ERR_PTR(rc);
 	}