diff options
authorTomi Valkeinen <tomi.valkeinen@ti.com>2020-05-27 10:23:34 +0200
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-06-11 19:20:55 +0200
commit0d9668721311607353d4861e6c32afeb272813dc (patch)
parent5be5f41dd785a67cf4e1dc07a3454e340a94b2e0 (diff)
media: videobuf2-dma-contig: fix bad kfree in vb2_dma_contig_clear_max_seg_size
Commit 9495b7e92f716ab2bd6814fab5e97ab4a39adfdd ("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: 9495b7e92f71 ("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>
2 files changed, 3 insertions, 19 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index d3a3ee5b597b..f4b4a7c135eb 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -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)
- * 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;
MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h
index 5604818d137e..5be313cbf7d7 100644
--- a/include/media/videobuf2-dma-contig.h
+++ b/include/media/videobuf2-dma-contig.h
@@ -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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