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

From: Dan Carpenter
Date: Tue Jul 13 2021 - 05:24:43 EST


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@xxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
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