| Message ID | 20190314050344.29790-1-kjlu@umn.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] media: rga: fix NULL pointer dereferences, use-after-free, memory leak | expand |
On 14/03/2019 05:03, 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@umn.edu> Reviewed-by: Steven Price <steven.price@arm.com> Yes, that looks like it solves the issues with the clean up - thanks for reworking it! > --- > 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; > + } > > 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); Minor comment: free_pages accepts a NULL pointer (or more precisely 0, since it takes an unsigned long), it just returns having done nothing. So there isn't actually any harm in calling free_pages unconditionally in the error path (since rga is initialised to all zeros). You can save a couple of labels in the error path using that trick. Thanks, Steve > +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: >
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@umn.edu> > --- > 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! 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: >
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@umn.edu> >> --- >> 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: >>
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; + } 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:
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@umn.edu> --- drivers/media/platform/rockchip/rga/rga.c | 26 ++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)