From 55b0f4a7c37680428d640aeada96d62888366c56 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 30 Nov 2023 10:27:15 +0300 Subject: [PATCH] drm/imagination: fix off by one in pvr_vm_mips_init() error handling If the call to vmap() fails the "page_nr" is one element beyond the end of the mips_data->pt_dma_addr[] and mips_data->pt_pages[] arrays. The way that this is traditionally written is that we clean up the partial loop iteration before the goto and then we can say while (--i >= 0). At that point we know that all the elements thus far are initialized so we don't need to have NULL checks. Fixes: 927f3e0253c1 ("drm/imagination: Implement MIPS firmware processor and MMU support") Signed-off-by: Dan Carpenter Reviewed-by: Frank Binns Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/a2d3210b-290f-4397-9c3e-efdcca94d8ac@moroto.mountain --- drivers/gpu/drm/imagination/pvr_vm_mips.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/imagination/pvr_vm_mips.c b/drivers/gpu/drm/imagination/pvr_vm_mips.c index 7268cf6e630b..2bc7181a4c3e 100644 --- a/drivers/gpu/drm/imagination/pvr_vm_mips.c +++ b/drivers/gpu/drm/imagination/pvr_vm_mips.c @@ -57,6 +57,7 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev) PAGE_SIZE, DMA_TO_DEVICE); if (dma_mapping_error(dev, mips_data->pt_dma_addr[page_nr])) { err = -ENOMEM; + __free_page(mips_data->pt_pages[page_nr]); goto err_free_pages; } } @@ -79,13 +80,11 @@ pvr_vm_mips_init(struct pvr_device *pvr_dev) return 0; err_free_pages: - for (; page_nr >= 0; page_nr--) { - if (mips_data->pt_dma_addr[page_nr]) - dma_unmap_page(from_pvr_device(pvr_dev)->dev, - mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE); + while (--page_nr >= 0) { + dma_unmap_page(from_pvr_device(pvr_dev)->dev, + mips_data->pt_dma_addr[page_nr], PAGE_SIZE, DMA_TO_DEVICE); - if (mips_data->pt_pages[page_nr]) - __free_page(mips_data->pt_pages[page_nr]); + __free_page(mips_data->pt_pages[page_nr]); } return err; -- 2.45.0