| Message ID | 20230817235859.49846-14-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | dmaengine: Annotate with __counted_by | expand |
On 8/17/23 17:58, Kees Cook wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct stm32_mdma_device. > Additionally, since the element count member must be set before accessing > the annotated flexible array member, move its initialization earlier. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > Cc: Vinod Koul <vkoul@kernel.org> > Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> > Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> > Cc: dmaengine@vger.kernel.org > Cc: linux-stm32@st-md-mailman.stormreply.com > Cc: linux-arm-kernel@lists.infradead.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks -- Gustavo > --- > drivers/dma/stm32-mdma.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c > index 926d6ecf1274..0c7d2295856e 100644 > --- a/drivers/dma/stm32-mdma.c > +++ b/drivers/dma/stm32-mdma.c > @@ -256,7 +256,7 @@ struct stm32_mdma_device { > u32 nr_ahb_addr_masks; > u32 chan_reserved; > struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS]; > - u32 ahb_addr_masks[]; > + u32 ahb_addr_masks[] __counted_by(nr_ahb_addr_masks); > }; > > static struct stm32_mdma_device *stm32_mdma_get_dev( > @@ -1611,13 +1611,13 @@ static int stm32_mdma_probe(struct platform_device *pdev) > GFP_KERNEL); > if (!dmadev) > return -ENOMEM; > + dmadev->nr_ahb_addr_masks = count; > > dmadev->nr_channels = nr_channels; > dmadev->nr_requests = nr_requests; > device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks", > dmadev->ahb_addr_masks, > count); > - dmadev->nr_ahb_addr_masks = count; > > dmadev->base = devm_platform_ioremap_resource(pdev, 0); > if (IS_ERR(dmadev->base))
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c index 926d6ecf1274..0c7d2295856e 100644 --- a/drivers/dma/stm32-mdma.c +++ b/drivers/dma/stm32-mdma.c @@ -256,7 +256,7 @@ struct stm32_mdma_device { u32 nr_ahb_addr_masks; u32 chan_reserved; struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS]; - u32 ahb_addr_masks[]; + u32 ahb_addr_masks[] __counted_by(nr_ahb_addr_masks); }; static struct stm32_mdma_device *stm32_mdma_get_dev( @@ -1611,13 +1611,13 @@ static int stm32_mdma_probe(struct platform_device *pdev) GFP_KERNEL); if (!dmadev) return -ENOMEM; + dmadev->nr_ahb_addr_masks = count; dmadev->nr_channels = nr_channels; dmadev->nr_requests = nr_requests; device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks", dmadev->ahb_addr_masks, count); - dmadev->nr_ahb_addr_masks = count; dmadev->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(dmadev->base))
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct stm32_mdma_device. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Vinod Koul <vkoul@kernel.org> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: dmaengine@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/dma/stm32-mdma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)