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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, Dan Carpenter <dan.carpenter@oracle.com>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 367/677] media: atomisp: Fix use after free in atomisp_alloc_css_stat_bufs()
Date:   Wed, 12 May 2021 16:46:53 +0200
Message-Id: <20210512144849.521353493@linuxfoundation.org>
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From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit ba11bbf303fafb33989e95473e409f6ab412b18d ]

The "s3a_buf" is freed along with all the other items on the
"asd->s3a_stats" list.  It leads to a double free and a use after free.

Link: https://lore.kernel.org/linux-media/X9dSO3RGf7r0pq2k@mwanda
Fixes: ad85094b293e ("Revert "media: staging: atomisp: Remove driver"")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/staging/media/atomisp/pci/atomisp_ioctl.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
index 2ae50decfc8b..9da82855552d 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_ioctl.c
@@ -948,10 +948,8 @@ int atomisp_alloc_css_stat_bufs(struct atomisp_sub_device *asd,
 		dev_dbg(isp->dev, "allocating %d dis buffers\n", count);
 		while (count--) {
 			dis_buf = kzalloc(sizeof(struct atomisp_dis_buf), GFP_KERNEL);
-			if (!dis_buf) {
-				kfree(s3a_buf);
+			if (!dis_buf)
 				goto error;
-			}
 			if (atomisp_css_allocate_stat_buffers(
 				asd, stream_id, NULL, dis_buf, NULL)) {
 				kfree(dis_buf);
-- 
2.30.2