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From:   Ricardo Ribalda <ribalda@chromium.org>
To:     Tomasz Figa <tfiga@chromium.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     Ricardo Ribalda <ribalda@chromium.org>, stable@vger.kernel.org
Subject: [PATCH] media: videobuf2: Fix integer overrun in allocation
Date:   Wed, 10 Mar 2021 00:43:17 +0100
Message-Id: <20210309234317.1021588-1-ribalda@chromium.org>
MIME-Version: 1.0
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Precedence: bulk

The plane_length is an unsigned integer. So, if we have a size of
0xffffffff bytes we incorrectly allocate 0 bytes instead of 1 << 32.

Cc: stable@vger.kernel.org
Fixes: 7f8414594e47 ("[media] media: videobuf2: fix the length check for mmap")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 02281d13505f..543da515c761 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -223,8 +223,10 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 	 * NOTE: mmapped areas should be page aligned
 	 */
 	for (plane = 0; plane < vb->num_planes; ++plane) {
+		unsigned long size = vb->planes[plane].length;
+
 		/* Memops alloc requires size to be page aligned. */
-		unsigned long size = PAGE_ALIGN(vb->planes[plane].length);
+		size = PAGE_ALIGN(size);
 
 		/* Did it wrap around? */
 		if (size < vb->planes[plane].length)
-- 
2.30.1.766.gb4fecdf3b7-goog