From fd1cb31a037bf8894a710392c2354281c5276d09 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 17 Aug 2023 16:58:43 -0700 Subject: [PATCH] dmaengine: moxart-dma: Annotate struct moxart_desc with __counted_by 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 moxart_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 Cc: dmaengine@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: "Gustavo A. R. Silva" Link: https://lore.kernel.org/r/20230817235859.49846-6-keescook@chromium.org Signed-off-by: Vinod Koul --- drivers/dma/moxart-dma.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/dma/moxart-dma.c b/drivers/dma/moxart-dma.c index a03953b3016b..c48d68cbff92 100644 --- a/drivers/dma/moxart-dma.c +++ b/drivers/dma/moxart-dma.c @@ -124,7 +124,7 @@ struct moxart_desc { unsigned int dma_cycles; struct virt_dma_desc vd; uint8_t es; - struct moxart_sg sg[]; + struct moxart_sg sg[] __counted_by(sglen); }; struct moxart_chan { @@ -309,6 +309,7 @@ static struct dma_async_tx_descriptor *moxart_prep_slave_sg( d = kzalloc(struct_size(d, sg, sg_len), GFP_ATOMIC); if (!d) return NULL; + d->sglen = sg_len; d->dma_dir = dir; d->dev_addr = dev_addr; @@ -319,8 +320,6 @@ static struct dma_async_tx_descriptor *moxart_prep_slave_sg( d->sg[i].len = sg_dma_len(sgent); } - d->sglen = sg_len; - ch->error = 0; return vchan_tx_prep(&ch->vc, &d->vd, tx_flags);