From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() When dma_device_put() drops the last reference on chan->device->ref, dma_device_release() runs and may free the dma_device along with its channels. dma_chan_put() then still reads chan->device->owner via dma_chan_to_owner() for the trailing module_put(). KASAN catches it: slab-use-after-free in dma_chan_put+0x3e6/0x4c0 Read of size 8 by task insmod/6319 Freed by task 6319: kfree+0x225/0x470 dma_chan_put+0x395/0x4c0 dmaengine_put+0xf8/0x160 Cache the module owner in dma_chan_put() before the put so the trailing module_put() does not need chan->device. Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") Suggested-by: Sashiko Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- drivers/fpga/xilinx-selectmap.c | 94 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 drivers/fpga/xilinx-selectmap.c (limited to 'drivers/fpga/xilinx-selectmap.c') diff --git a/drivers/fpga/xilinx-selectmap.c b/drivers/fpga/xilinx-selectmap.c new file mode 100644 index 000000000..d0cbb5fdf --- /dev/null +++ b/drivers/fpga/xilinx-selectmap.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Xilinx Spartan6 and 7 Series SelectMAP interface driver + * + * (C) 2024 Charles Perry + * + * Manage Xilinx FPGA firmware loaded over the SelectMAP configuration + * interface. + */ + +#include "xilinx-core.h" + +#include +#include +#include +#include +#include + +struct xilinx_selectmap_conf { + struct xilinx_fpga_core core; + void __iomem *base; +}; + +#define to_xilinx_selectmap_conf(obj) \ + container_of(obj, struct xilinx_selectmap_conf, core) + +static int xilinx_selectmap_write(struct xilinx_fpga_core *core, + const char *buf, size_t count) +{ + struct xilinx_selectmap_conf *conf = to_xilinx_selectmap_conf(core); + size_t i; + + for (i = 0; i < count; ++i) + writeb(buf[i], conf->base); + + return 0; +} + +static int xilinx_selectmap_probe(struct platform_device *pdev) +{ + struct xilinx_selectmap_conf *conf; + struct gpio_desc *gpio; + void __iomem *base; + + conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL); + if (!conf) + return -ENOMEM; + + conf->core.dev = &pdev->dev; + conf->core.write = xilinx_selectmap_write; + + base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); + if (IS_ERR(base)) + return dev_err_probe(&pdev->dev, PTR_ERR(base), + "ioremap error\n"); + conf->base = base; + + /* CSI_B is active low */ + gpio = devm_gpiod_get_optional(&pdev->dev, "csi", GPIOD_OUT_HIGH); + if (IS_ERR(gpio)) + return dev_err_probe(&pdev->dev, PTR_ERR(gpio), + "Failed to get CSI_B gpio\n"); + + /* RDWR_B is active low */ + gpio = devm_gpiod_get_optional(&pdev->dev, "rdwr", GPIOD_OUT_HIGH); + if (IS_ERR(gpio)) + return dev_err_probe(&pdev->dev, PTR_ERR(gpio), + "Failed to get RDWR_B gpio\n"); + + return xilinx_core_probe(&conf->core); +} + +static const struct of_device_id xlnx_selectmap_of_match[] = { + { .compatible = "xlnx,fpga-xc7s-selectmap", }, // Spartan-7 + { .compatible = "xlnx,fpga-xc7a-selectmap", }, // Artix-7 + { .compatible = "xlnx,fpga-xc7k-selectmap", }, // Kintex-7 + { .compatible = "xlnx,fpga-xc7v-selectmap", }, // Virtex-7 + {}, +}; +MODULE_DEVICE_TABLE(of, xlnx_selectmap_of_match); + +static struct platform_driver xilinx_selectmap_driver = { + .driver = { + .name = "xilinx-selectmap", + .of_match_table = xlnx_selectmap_of_match, + }, + .probe = xilinx_selectmap_probe, +}; + +module_platform_driver(xilinx_selectmap_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Charles Perry "); +MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SelectMap"); -- cgit v1.3.1