* drivers/mtd/nand/raw/cadence-nand-controller.c:2956 cadence_nand_init() warn: variable dereferenced before check 'cdns_ctrl->dmac' (see line 2918)
@ 2026-03-25 15:26 Dan Carpenter
0 siblings, 0 replies; only message in thread
From: Dan Carpenter @ 2026-03-25 15:26 UTC (permalink / raw)
To: oe-kbuild, Niravkumar L Rabara
Cc: lkp, oe-kbuild-all, linux-kernel, Miquel Raynal
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: bbeb83d3182abe0d245318e274e8531e5dd7a948
commit: 5c56bf214af85ca042bf97f8584aab2151035840 mtd: rawnand: cadence: fix DMA device NULL pointer dereference
config: openrisc-randconfig-r073-20260325 (https://download.01.org/0day-ci/archive/20260325/202603252339.fQzI6oc8-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 15.2.0
smatch: v0.5.0-9004-gb810ac53
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202603252339.fQzI6oc8-lkp@intel.com/
smatch warnings:
drivers/mtd/nand/raw/cadence-nand-controller.c:2956 cadence_nand_init() warn: variable dereferenced before check 'cdns_ctrl->dmac' (see line 2918)
vim +2956 drivers/mtd/nand/raw/cadence-nand-controller.c
ec4ba01e894d316 Piotr Sroka 2019-09-26 2871 static int cadence_nand_init(struct cdns_nand_ctrl *cdns_ctrl)
ec4ba01e894d316 Piotr Sroka 2019-09-26 2872 {
ec4ba01e894d316 Piotr Sroka 2019-09-26 2873 dma_cap_mask_t mask;
5c56bf214af85ca Niravkumar L Rabara 2025-10-23 2874 struct dma_device *dma_dev;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2875 int ret;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2876
ec4ba01e894d316 Piotr Sroka 2019-09-26 2877 cdns_ctrl->cdma_desc = dma_alloc_coherent(cdns_ctrl->dev,
ec4ba01e894d316 Piotr Sroka 2019-09-26 2878 sizeof(*cdns_ctrl->cdma_desc),
ec4ba01e894d316 Piotr Sroka 2019-09-26 2879 &cdns_ctrl->dma_cdma_desc,
ec4ba01e894d316 Piotr Sroka 2019-09-26 2880 GFP_KERNEL);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2881 if (!cdns_ctrl->dma_cdma_desc)
ec4ba01e894d316 Piotr Sroka 2019-09-26 2882 return -ENOMEM;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2883
ec4ba01e894d316 Piotr Sroka 2019-09-26 2884 cdns_ctrl->buf_size = SZ_16K;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2885 cdns_ctrl->buf = kmalloc(cdns_ctrl->buf_size, GFP_KERNEL);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2886 if (!cdns_ctrl->buf) {
ec4ba01e894d316 Piotr Sroka 2019-09-26 2887 ret = -ENOMEM;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2888 goto free_buf_desc;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2889 }
ec4ba01e894d316 Piotr Sroka 2019-09-26 2890
ec4ba01e894d316 Piotr Sroka 2019-09-26 2891 if (devm_request_irq(cdns_ctrl->dev, cdns_ctrl->irq, cadence_nand_isr,
ec4ba01e894d316 Piotr Sroka 2019-09-26 2892 IRQF_SHARED, "cadence-nand-controller",
ec4ba01e894d316 Piotr Sroka 2019-09-26 2893 cdns_ctrl)) {
ec4ba01e894d316 Piotr Sroka 2019-09-26 2894 dev_err(cdns_ctrl->dev, "Unable to allocate IRQ\n");
ec4ba01e894d316 Piotr Sroka 2019-09-26 2895 ret = -ENODEV;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2896 goto free_buf;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2897 }
ec4ba01e894d316 Piotr Sroka 2019-09-26 2898
ec4ba01e894d316 Piotr Sroka 2019-09-26 2899 spin_lock_init(&cdns_ctrl->irq_lock);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2900 init_completion(&cdns_ctrl->complete);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2901
ec4ba01e894d316 Piotr Sroka 2019-09-26 2902 ret = cadence_nand_hw_init(cdns_ctrl);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2903 if (ret)
ec4ba01e894d316 Piotr Sroka 2019-09-26 2904 goto disable_irq;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2905
ec4ba01e894d316 Piotr Sroka 2019-09-26 2906 dma_cap_zero(mask);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2907 dma_cap_set(DMA_MEMCPY, mask);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2908
ec4ba01e894d316 Piotr Sroka 2019-09-26 2909 if (cdns_ctrl->caps1->has_dma) {
2b9df00cded911e Niravkumar L Rabara 2025-02-10 2910 cdns_ctrl->dmac = dma_request_chan_by_mask(&mask);
^^^^^^^^^^^^^^^
->dmac assigned here.
2b9df00cded911e Niravkumar L Rabara 2025-02-10 2911 if (IS_ERR(cdns_ctrl->dmac)) {
2b9df00cded911e Niravkumar L Rabara 2025-02-10 2912 ret = dev_err_probe(cdns_ctrl->dev, PTR_ERR(cdns_ctrl->dmac),
2b9df00cded911e Niravkumar L Rabara 2025-02-10 2913 "%d: Failed to get a DMA channel\n", ret);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2914 goto disable_irq;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2915 }
ec4ba01e894d316 Piotr Sroka 2019-09-26 2916 }
ec4ba01e894d316 Piotr Sroka 2019-09-26 2917
5c56bf214af85ca Niravkumar L Rabara 2025-10-23 @2918 dma_dev = cdns_ctrl->dmac->device;
This feels like it should be in the if statement. Smatch complains that
we check it for NULL later.
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2919 cdns_ctrl->io.iova_dma = dma_map_resource(dma_dev->dev, cdns_ctrl->io.dma,
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2920 cdns_ctrl->io.size,
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2921 DMA_BIDIRECTIONAL, 0);
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2922
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2923 ret = dma_mapping_error(dma_dev->dev, cdns_ctrl->io.iova_dma);
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2924 if (ret) {
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2925 dev_err(cdns_ctrl->dev, "Failed to map I/O resource to DMA\n");
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2926 goto dma_release_chnl;
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2927 }
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2928
ec4ba01e894d316 Piotr Sroka 2019-09-26 2929 nand_controller_init(&cdns_ctrl->controller);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2930 INIT_LIST_HEAD(&cdns_ctrl->chips);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2931
ec4ba01e894d316 Piotr Sroka 2019-09-26 2932 cdns_ctrl->controller.ops = &cadence_nand_controller_ops;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2933 cdns_ctrl->curr_corr_str_idx = 0xFF;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2934
ec4ba01e894d316 Piotr Sroka 2019-09-26 2935 ret = cadence_nand_chips_init(cdns_ctrl);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2936 if (ret) {
ec4ba01e894d316 Piotr Sroka 2019-09-26 2937 dev_err(cdns_ctrl->dev, "Failed to register MTD: %d\n",
ec4ba01e894d316 Piotr Sroka 2019-09-26 2938 ret);
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2939 goto unmap_dma_resource;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2940 }
ec4ba01e894d316 Piotr Sroka 2019-09-26 2941
ec4ba01e894d316 Piotr Sroka 2019-09-26 2942 kfree(cdns_ctrl->buf);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2943 cdns_ctrl->buf = kzalloc(cdns_ctrl->buf_size, GFP_KERNEL);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2944 if (!cdns_ctrl->buf) {
ec4ba01e894d316 Piotr Sroka 2019-09-26 2945 ret = -ENOMEM;
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2946 goto unmap_dma_resource;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2947 }
ec4ba01e894d316 Piotr Sroka 2019-09-26 2948
ec4ba01e894d316 Piotr Sroka 2019-09-26 2949 return 0;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2950
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2951 unmap_dma_resource:
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2952 dma_unmap_resource(dma_dev->dev, cdns_ctrl->io.iova_dma,
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2953 cdns_ctrl->io.size, DMA_BIDIRECTIONAL, 0);
d76d22b5096c5b0 Niravkumar L Rabara 2025-02-10 2954
ec4ba01e894d316 Piotr Sroka 2019-09-26 2955 dma_release_chnl:
ec4ba01e894d316 Piotr Sroka 2019-09-26 @2956 if (cdns_ctrl->dmac)
^^^^^^^^^^^^^^^
Checked here.
ec4ba01e894d316 Piotr Sroka 2019-09-26 2957 dma_release_channel(cdns_ctrl->dmac);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2958
ec4ba01e894d316 Piotr Sroka 2019-09-26 2959 disable_irq:
ec4ba01e894d316 Piotr Sroka 2019-09-26 2960 cadence_nand_irq_cleanup(cdns_ctrl->irq, cdns_ctrl);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2961
ec4ba01e894d316 Piotr Sroka 2019-09-26 2962 free_buf:
ec4ba01e894d316 Piotr Sroka 2019-09-26 2963 kfree(cdns_ctrl->buf);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2964
ec4ba01e894d316 Piotr Sroka 2019-09-26 2965 free_buf_desc:
ec4ba01e894d316 Piotr Sroka 2019-09-26 2966 dma_free_coherent(cdns_ctrl->dev, sizeof(struct cadence_nand_cdma_desc),
ec4ba01e894d316 Piotr Sroka 2019-09-26 2967 cdns_ctrl->cdma_desc, cdns_ctrl->dma_cdma_desc);
ec4ba01e894d316 Piotr Sroka 2019-09-26 2968
ec4ba01e894d316 Piotr Sroka 2019-09-26 2969 return ret;
ec4ba01e894d316 Piotr Sroka 2019-09-26 2970 }
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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2026-03-25 15:26 drivers/mtd/nand/raw/cadence-nand-controller.c:2956 cadence_nand_init() warn: variable dereferenced before check 'cdns_ctrl->dmac' (see line 2918) Dan Carpenter
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