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Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > In mmp_pdma_prep_slave_sg(), for_each_sg() iterates the scatterlist > putting each entry into 'sg', but the entry length is read from 'sgl' > (the list head) instead of 'sg' (the current entry): > > for_each_sg(sgl, sg, sg_len, i) { > addr = sg_dma_address(sg); > avail = sg_dma_len(sgl); /* should be 'sg' */ > > Consequently 'avail' is always the length of the first entry. For > multi-sg lists this causes out-of-bounds reads when a later entry is > shorter than the first, and silent data loss when it is longer. > Single-sg or uniformly-sized lists happen to mask the issue. > > Fixes: c8acd6aa6bed3 ("dmaengine: mmp-pdma support") > Signed-off-by: Baineng Shou > --- Don't post new v2 patch to old email v1 thread. Reviewed-by: Frank Li > > Changes in v2: > - Add () to the function name in the subject, per Frank Li's review. > > drivers/dma/mmp_pdma.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c > index 386e85cd4882..e90fd2023af7 100644 > --- a/drivers/dma/mmp_pdma.c > +++ b/drivers/dma/mmp_pdma.c > @@ -713,7 +713,7 @@ mmp_pdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, > > for_each_sg(sgl, sg, sg_len, i) { > addr = sg_dma_address(sg); > - avail = sg_dma_len(sgl); > + avail = sg_dma_len(sg); > > do { > len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES); > -- > 2.34.1 >