linux-kernel - [PATCH v2] media: rockchip/rga: fix error handling in probe

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Message-ID: <YO1burFzVK+l3JST@mwanda>
Date:   Tue, 13 Jul 2021 12:24:10 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Jacob Chen <jacob-chen@...wrt.com>
Cc:     Ezequiel Garcia <ezequiel@...labora.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Heiko Stuebner <heiko@...ech.de>, linux-media@...r.kernel.org,
        linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org,
        Dongliang Mu <mudongliangabcd@...il.com>
Subject: [PATCH v2] media: rockchip/rga: fix error handling in probe

There are a few bugs in this code.  1)  No checks for whether
dma_alloc_attrs() or __get_free_pages() failed.  2)  If
video_register_device() fails it doesn't clean up the dma attrs or the
free pages.  3)  The video_device_release() function frees "vfd" which
leads to a use after free on the next line.  The call to
video_unregister_device() is not required so I have just removed that.

Fixes: f7e7b48e6d79 ("[media] rockchip/rga: v4l2 m2m support")
Reported-by: Dongliang Mu <mudongliangabcd@...il.com>
Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
---
v2:  The v1 patch only fixed the use after free and not the other bugs

 drivers/media/platform/rockchip/rga/rga.c | 27 ++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index bf3fd71ec3af..6759091b15e0 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -863,12 +863,12 @@ static int rga_probe(struct platform_device *pdev)
 	if (IS_ERR(rga->m2m_dev)) {
 		v4l2_err(&rga->v4l2_dev, "Failed to init mem2mem device\n");
 		ret = PTR_ERR(rga->m2m_dev);
-		goto unreg_video_dev;
+		goto rel_vdev;
 	}
 
 	ret = pm_runtime_resume_and_get(rga->dev);
 	if (ret < 0)
-		goto unreg_video_dev;
+		goto rel_vdev;
 
 	rga->version.major = (rga_read(rga, RGA_VERSION_INFO) >> 24) & 0xFF;
 	rga->version.minor = (rga_read(rga, RGA_VERSION_INFO) >> 20) & 0x0F;
@@ -882,11 +882,23 @@ static int rga_probe(struct platform_device *pdev)
 	rga->cmdbuf_virt = dma_alloc_attrs(rga->dev, RGA_CMDBUF_SIZE,
 					   &rga->cmdbuf_phy, GFP_KERNEL,
 					   DMA_ATTR_WRITE_COMBINE);
+	if (!rga->cmdbuf_virt) {
+		ret = -ENOMEM;
+		goto rel_vdev;
+	}
 
 	rga->src_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (!rga->src_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_dma;
+	}
 	rga->dst_mmu_pages =
 		(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+	if (rga->dst_mmu_pages) {
+		ret = -ENOMEM;
+		goto free_src_pages;
+	}
 
 	def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
 	def_frame.size = def_frame.stride * def_frame.height;
@@ -894,7 +906,7 @@ static int rga_probe(struct platform_device *pdev)
 	ret = video_register_device(vfd, VFL_TYPE_VIDEO, -1);
 	if (ret) {
 		v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
-		goto rel_vdev;
+		goto free_dst_pages;
 	}
 
 	v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -902,10 +914,15 @@ static int rga_probe(struct platform_device *pdev)
 
 	return 0;
 
+free_dst_pages:
+	free_pages((unsigned long)rga->dst_mmu_pages, 3);
+free_src_pages:
+	free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dma:
+	dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
+		       rga->cmdbuf_phy, DMA_ATTR_WRITE_COMBINE);
 rel_vdev:
 	video_device_release(vfd);
-unreg_video_dev:
-	video_unregister_device(rga->vfd);
 unreg_v4l2_dev:
 	v4l2_device_unregister(&rga->v4l2_dev);
 err_put_clk:
-- 
2.30.2