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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jianglei Nie <niejianglei2021@163.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0251/1017] crypto: ccree - Fix use after free in cc_cipher_exit()
Date:   Tue,  5 Apr 2022 09:19:24 +0200
Message-Id: <20220405070401.712674946@linuxfoundation.org>
In-Reply-To: <20220405070354.155796697@linuxfoundation.org>
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From: Jianglei Nie <niejianglei2021@163.com>

[ Upstream commit 3d950c34074ed74d2713c3856ba01264523289e6 ]

kfree_sensitive(ctx_p->user.key) will free the ctx_p->user.key. But
ctx_p->user.key is still used in the next line, which will lead to a
use after free.

We can call kfree_sensitive() after dev_dbg() to avoid the uaf.

Fixes: 63ee04c8b491 ("crypto: ccree - add skcipher support")
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/ccree/cc_cipher.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/ccree/cc_cipher.c b/drivers/crypto/ccree/cc_cipher.c
index 78833491f534..309da6334a0a 100644
--- a/drivers/crypto/ccree/cc_cipher.c
+++ b/drivers/crypto/ccree/cc_cipher.c
@@ -257,8 +257,8 @@ static void cc_cipher_exit(struct crypto_tfm *tfm)
 		&ctx_p->user.key_dma_addr);
 
 	/* Free key buffer in context */
-	kfree_sensitive(ctx_p->user.key);
 	dev_dbg(dev, "Free key buffer in context. key=@%p\n", ctx_p->user.key);
+	kfree_sensitive(ctx_p->user.key);
 }
 
 struct tdes_keys {
-- 
2.34.1