Re: [PATCH] media: rga: fix NULL pointer dereferences
From: Steven Price <steven.price@arm.com>
Date: 2019-03-11 13:16:04
Also in:
linux-media, linux-rockchip, lkml
On 09/03/2019 06:35, Kangjie Lu wrote:
quoted hunk ↗ jump to hunk
In case __get_free_pages fails, return -ENOMEM to avoid NULL pointer dereferences. Signed-off-by: Kangjie Lu <redacted> --- drivers/media/platform/rockchip/rga/rga.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c index 5c653287185f..d42b214977a9 100644 --- a/drivers/media/platform/rockchip/rga/rga.c +++ b/drivers/media/platform/rockchip/rga/rga.c@@ -892,8 +892,13 @@ static int rga_probe(struct platform_device *pdev) rga->src_mmu_pages = (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3); + if (!rga->src_mmu_pages) + return -ENOMEM; + rga->dst_mmu_pages = (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3); + if (!rga->dst_mmu_pages) + return -ENOMEM;
I believe you need to perform clean up when probe fails, not just return early, e.g. with a 'goto' to the existing clean up code at the end of the function. Also from what I can tell there is already a potential memory leak if video_register_device() fails. You probably want something more like the (completely untested) change below. Steve ----8<----
diff --git a/drivers/media/platform/rockchip/rga/rga.cb/drivers/media/platform/rockchip/rga/rga.c index 5c653287185f..8df1945594ab 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c@@ -895,6 +895,11 @@ static int rga_probe(struct platform_device *pdev) rga->dst_mmu_pages = (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3); + if (!rga->src_mmu_pages || !rga->dst_mmu_pages) { + ret = -ENOMEM; + goto free_mem; + } + def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3; def_frame.size = def_frame.stride * def_frame.height;
@@ -911,6 +916,9 @@ static int rga_probe(struct platform_device *pdev) rel_vdev: video_device_release(vfd); +free_mem: + free_pages((unsigned long)rga->src_mmu_pages, 3); + free_pages((unsigned long)rga->dst_mmu_pages, 3); unreg_video_dev: video_unregister_device(rga->vfd); unreg_v4l2_dev:
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