| Message ID | 20230817235859.49846-18-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 omap_desc. > 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: Peter Ujfalusi <peter.ujfalusi@gmail.com> > Cc: dmaengine@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks -- Gustavo > --- > drivers/dma/ti/omap-dma.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c > index cf96cf915c0c..11ac3fc0a52a 100644 > --- a/drivers/dma/ti/omap-dma.c > +++ b/drivers/dma/ti/omap-dma.c > @@ -124,7 +124,7 @@ struct omap_desc { > uint32_t csdp; /* CSDP value */ > > unsigned sglen; > - struct omap_sg sg[]; > + struct omap_sg sg[] __counted_by(sglen); > }; > > enum { > @@ -1005,6 +1005,7 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( > d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC); > if (!d) > return NULL; > + d->sglen = sglen; > > d->dir = dir; > d->dev_addr = dev_addr; > @@ -1120,8 +1121,6 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( > } > } > > - d->sglen = sglen; > - > /* Release the dma_pool entries if one allocation failed */ > if (ll_failed) { > for (i = 0; i < d->sglen; i++) {
diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c index cf96cf915c0c..11ac3fc0a52a 100644 --- a/drivers/dma/ti/omap-dma.c +++ b/drivers/dma/ti/omap-dma.c @@ -124,7 +124,7 @@ struct omap_desc { uint32_t csdp; /* CSDP value */ unsigned sglen; - struct omap_sg sg[]; + struct omap_sg sg[] __counted_by(sglen); }; enum { @@ -1005,6 +1005,7 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( d = kzalloc(struct_size(d, sg, sglen), GFP_ATOMIC); if (!d) return NULL; + d->sglen = sglen; d->dir = dir; d->dev_addr = dev_addr; @@ -1120,8 +1121,6 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( } } - d->sglen = sglen; - /* Release the dma_pool entries if one allocation failed */ if (ll_failed) { for (i = 0; i < d->sglen; i++) {
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 omap_desc. 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: Peter Ujfalusi <peter.ujfalusi@gmail.com> Cc: dmaengine@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/dma/ti/omap-dma.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)