media: videobuf2-dma-contig: fix bad kfree in vb2_dma_contig_clear_max_seg_size (0d966872) · Commits · 戴 / test

Commit ("driver core: platform: Initialize dma_parms for platform devices") in v5.7-rc5 causes vb2_dma_contig_clear_max_seg_size() to kfree memory that was not allocated by vb2_dma_contig_set_max_seg_size(). The assumption in vb2_dma_contig_set_max_seg_size() seems to be that dev->dma_parms is always NULL when the driver is probed, and the case where dev->dma_parms has bee initialized by someone else than the driver (by calling vb2_dma_contig_set_max_seg_size) will cause a failure. All the current users of these functions are platform devices, which now always have dma_parms set by the driver core. To fix the issue for v5.7, make vb2_dma_contig_set_max_seg_size() return an error if dma_parms is NULL to be on the safe side, and remove the kfree code from vb2_dma_contig_clear_max_seg_size(). For v5.8 we should remove the two functions and move the dma_set_max_seg_size() calls into the drivers. Signed-off-by:

Tomi Valkeinen <tomi.valkeinen@ti.com> Fixes: ("driver core: platform: Initialize dma_parms for platform devices") Cc: stable@vger.kernel.org Acked-by:

Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by:

Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by:

Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by:

Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/common/videobuf2/videobuf2-dma-contig.c

+2 −18

Original line number	Diff line number	Diff line
		@@ -726,9 +726,8 @@ EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
		int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size)
		{
		if (!dev->dma_parms) {
		dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
		if (!dev->dma_parms)
		return -ENOMEM;
		dev_err(dev, "Failed to set max_seg_size: dma_parms is NULL\n");
		return -ENODEV;
		}
		if (dma_get_max_seg_size(dev) < size)
		return dma_set_max_seg_size(dev, size);
		@@ -737,21 +736,6 @@ int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size)
		}
		EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size);

		/*
		* vb2_dma_contig_clear_max_seg_size() - release resources for DMA parameters
		* @dev: device for configuring DMA parameters
		*
		* This function releases resources allocated to configure DMA parameters
		* (see vb2_dma_contig_set_max_seg_size() function). It should be called from
		* device drivers on driver remove.
		*/
		void vb2_dma_contig_clear_max_seg_size(struct device *dev)
		{
		kfree(dev->dma_parms);
		dev->dma_parms = NULL;
		}
		EXPORT_SYMBOL_GPL(vb2_dma_contig_clear_max_seg_size);

		MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
		MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
		MODULE_LICENSE("GPL");

include/media/videobuf2-dma-contig.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -25,7 +25,7 @@ vb2_dma_contig_plane_dma_addr(struct vb2_buffer *vb, unsigned int plane_no)
		}

		int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size);
		void vb2_dma_contig_clear_max_seg_size(struct device *dev);
		static inline void vb2_dma_contig_clear_max_seg_size(struct device *dev) { }

		extern const struct vb2_mem_ops vb2_dma_contig_memops;

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