5.10-stable review patch. If anyone has any objections, please let me know.
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From: Mikhail Kobuk m.kobuk@ispras.ru
commit 629913d6d79508b166c66e07e4857e20233d85a9 upstream.
In case DMA fails, 'dma->SG_length' is 0. This value is later used to access 'dma->SGarray[dma->SG_length - 1]', which will cause out of bounds access.
Add check to return early on invalid value. Adjust warnings accordingly.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 1932dc2f4cf6 ("media: pci/ivtv: switch from 'pci_' to 'dma_' API") Signed-off-by: Mikhail Kobuk m.kobuk@ispras.ru Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/pci/ivtv/ivtv-udma.c | 8 ++++++++ drivers/media/pci/ivtv/ivtv-yuv.c | 6 ++++++ drivers/media/pci/ivtv/ivtvfb.c | 6 +++--- 3 files changed, 17 insertions(+), 3 deletions(-)
--- a/drivers/media/pci/ivtv/ivtv-udma.c +++ b/drivers/media/pci/ivtv/ivtv-udma.c @@ -131,6 +131,8 @@ int ivtv_udma_setup(struct ivtv *itv, un
/* Fill SG List with new values */ if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) { + IVTV_DEBUG_WARN("%s: could not allocate bounce buffers for highmem userspace buffers\n", + __func__); unpin_user_pages(dma->map, dma->page_count); dma->page_count = 0; return -ENOMEM; @@ -139,6 +141,12 @@ int ivtv_udma_setup(struct ivtv *itv, un /* Map SG List */ dma->SG_length = dma_map_sg(&itv->pdev->dev, dma->SGlist, dma->page_count, DMA_TO_DEVICE); + if (!dma->SG_length) { + IVTV_DEBUG_WARN("%s: DMA map error, SG_length is 0\n", __func__); + unpin_user_pages(dma->map, dma->page_count); + dma->page_count = 0; + return -EINVAL; + }
/* Fill SG Array with new values */ ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1); --- a/drivers/media/pci/ivtv/ivtv-yuv.c +++ b/drivers/media/pci/ivtv/ivtv-yuv.c @@ -115,6 +115,12 @@ static int ivtv_yuv_prep_user_dma(struct } dma->SG_length = dma_map_sg(&itv->pdev->dev, dma->SGlist, dma->page_count, DMA_TO_DEVICE); + if (!dma->SG_length) { + IVTV_DEBUG_WARN("%s: DMA map error, SG_length is 0\n", __func__); + unpin_user_pages(dma->map, dma->page_count); + dma->page_count = 0; + return -EINVAL; + }
/* Fill SG Array with new values */ ivtv_udma_fill_sg_array(dma, y_buffer_offset, uv_buffer_offset, y_size); --- a/drivers/media/pci/ivtv/ivtvfb.c +++ b/drivers/media/pci/ivtv/ivtvfb.c @@ -281,10 +281,10 @@ static int ivtvfb_prep_dec_dma_to_device /* Map User DMA */ if (ivtv_udma_setup(itv, ivtv_dest_addr, userbuf, size_in_bytes) <= 0) { mutex_unlock(&itv->udma.lock); - IVTVFB_WARN("ivtvfb_prep_dec_dma_to_device, Error with pin_user_pages: %d bytes, %d pages returned\n", - size_in_bytes, itv->udma.page_count); + IVTVFB_WARN("%s, Error in ivtv_udma_setup: %d bytes, %d pages returned\n", + __func__, size_in_bytes, itv->udma.page_count);
- /* pin_user_pages must have failed completely */ + /* pin_user_pages or DMA must have failed completely */ return -EIO; }