4.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Sergio Paracuellos <[email protected]> commit 354e379684fcc70ab8d5450b4d57bd92b5294dfd upstream. Function 'mtk_hsdma_start_transfer' uses 'tx_desc' pointer which can be dereferenced before it is initializated. Initializate pointer before avoiding the problem. Fixes: 0853c7a53eb3 ("staging: mt7621-dma: ralink: add rt2880 dma engine") Reported-by: Dan Carpenter <[email protected]> Signed-off-by: Sergio Paracuellos <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/staging/mt7621-dma/mtk-hsdma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/staging/mt7621-dma/mtk-hsdma.c +++ b/drivers/staging/mt7621-dma/mtk-hsdma.c @@ -335,6 +335,8 @@ static int mtk_hsdma_start_transfer(stru /* tx desc */ src = sg->src_addr; for (i = 0; i < chan->desc->num_sgs; i++) { + tx_desc = &chan->tx_ring[chan->tx_idx]; + if (len > HSDMA_MAX_PLEN) tlen = HSDMA_MAX_PLEN; else @@ -344,7 +346,6 @@ static int mtk_hsdma_start_transfer(stru tx_desc->addr1 = src; tx_desc->flags |= HSDMA_DESC_PLEN1(tlen); } else { - tx_desc = &chan->tx_ring[chan->tx_idx]; tx_desc->addr0 = src; tx_desc->flags = HSDMA_DESC_PLEN0(tlen);
