[PATCH 5.17 0258/1126] crypto: ccree - Fix use after free in cc_cipher_exit()

Greg Kroah-Hartman
2022-04-05T08:04:15Z

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