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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Yunfeng Ye <yeyunfeng@huawei.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Sasha Levin <sashal@kernel.org>, linux-crypto@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 26/33] crypto: hisilicon - Fix double free in sec_free_hw_sgl()
Date:   Sun, 29 Sep 2019 13:34:14 -0400
Message-Id: <20190929173424.9361-26-sashal@kernel.org>
In-Reply-To: <20190929173424.9361-1-sashal@kernel.org>
References: <20190929173424.9361-1-sashal@kernel.org>
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From: Yunfeng Ye <yeyunfeng@huawei.com>

[ Upstream commit 24fbf7bad888767bed952f540ac963bc57e47e15 ]

There are two problems in sec_free_hw_sgl():

First, when sgl_current->next is valid, @hw_sgl will be freed in the
first loop, but it free again after the loop.

Second, sgl_current and sgl_current->next_sgl is not match when
dma_pool_free() is invoked, the third parameter should be the dma
address of sgl_current, but sgl_current->next_sgl is the dma address
of next chain, so use sgl_current->next_sgl is wrong.

Fix this by deleting the last dma_pool_free() in sec_free_hw_sgl(),
modifying the condition for while loop, and matching the address for
dma_pool_free().

Fixes: 915e4e8413da ("crypto: hisilicon - SEC security accelerator driver")
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/hisilicon/sec/sec_algs.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/crypto/hisilicon/sec/sec_algs.c b/drivers/crypto/hisilicon/sec/sec_algs.c
index cdc4f9a171d98..db2983c51f1e6 100644
--- a/drivers/crypto/hisilicon/sec/sec_algs.c
+++ b/drivers/crypto/hisilicon/sec/sec_algs.c
@@ -215,17 +215,18 @@ static void sec_free_hw_sgl(struct sec_hw_sgl *hw_sgl,
 			    dma_addr_t psec_sgl, struct sec_dev_info *info)
 {
 	struct sec_hw_sgl *sgl_current, *sgl_next;
+	dma_addr_t sgl_next_dma;
 
-	if (!hw_sgl)
-		return;
 	sgl_current = hw_sgl;
-	while (sgl_current->next) {
+	while (sgl_current) {
 		sgl_next = sgl_current->next;
-		dma_pool_free(info->hw_sgl_pool, sgl_current,
-			      sgl_current->next_sgl);
+		sgl_next_dma = sgl_current->next_sgl;
+
+		dma_pool_free(info->hw_sgl_pool, sgl_current, psec_sgl);
+
 		sgl_current = sgl_next;
+		psec_sgl = sgl_next_dma;
 	}
-	dma_pool_free(info->hw_sgl_pool, hw_sgl, psec_sgl);
 }
 
 static int sec_alg_skcipher_setkey(struct crypto_skcipher *tfm,
-- 
2.20.1