On 3/28/19 9:47 AM, Hans Verkuil wrote:
Hi Kangjie,
Unfortunately there are more issues with the cleanup sequence in
this probe function:
On 3/14/19 6:03 AM, Kangjie Lu wrote:
1. dma_alloc_attrs, __get_free_pages can fail and return NULL.
Further uses of their return values lead to NULL pointer
dereferences
2. In the error-handling path, video_unregister_device uses
"rga->vfd" which has been freed by video_device_release
3. The error handling for v4l2_m2m_init and video_register_device
has memory-leak issues
The patch fixes the above issues.
Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
---
drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..468365ceb99d 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -889,11 +889,24 @@ 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 unreg_video_dev;
Actually, the unreg_video_dev label makes no sense: if the video device
is successfully registered, then probe() returns 0. So you never need to
unregister the video device again. You *do* need to release it with
video_device_release().
So this should be a goto rel_vdev.
And the cleanup sequence at the end also fails to call v4l2_m2m_release().
Can you make v4?
Thanks for the feedback. Will send a v4.
Thanks!
Hans
+ }
rga->src_mmu_pages =
(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+ if (!rga->src_mmu_pages) {
+ ret = -ENOMEM;
+ goto free_dma_attrs;
+ }
+
rga->dst_mmu_pages =
(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+ if (!rga->dst_mmu_pages) {
+ ret = -ENOMEM;
+ goto free_dst_pages;
+ }
def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
def_frame.size = def_frame.stride * def_frame.height;
@@ -901,7 +914,7 @@ static int rga_probe(struct platform_device *pdev)
ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
if (ret) {
v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
- goto rel_vdev;
+ goto free_pages;
}
v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -909,10 +922,17 @@ static int rga_probe(struct platform_device *pdev)
return 0;
-rel_vdev:
- video_device_release(vfd);
+free_pages:
+ free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dst_pages:
+ free_pages((unsigned long)rga->dst_mmu_pages, 3);
+free_dma_attrs:
+ dma_free_attrs(rga->dev, RGA_CMDBUF_SIZE, rga->cmdbuf_virt,
+ rga->cmdbuf_phy,
+ DMA_ATTR_WRITE_COMBINE);
unreg_video_dev:
video_unregister_device(rga->vfd);
+ video_device_release(vfd);
unreg_v4l2_dev:
v4l2_device_unregister(&rga->v4l2_dev);
err_put_clk:
