From: "Alexander.Barabash@xxxxxxxx" <Alexander.Barabash@xxxxxxxx> [ Upstream commit b0b5ce1010ffc50015eaec72b0028aaae3f526bb ] If dma_alloc_coherent() returns NULL in ioat_alloc_ring(), ring allocation must not proceed. Until now, if the first call to dma_alloc_coherent() in ioat_alloc_ring() returned NULL, the processing could proceed, failing with NULL-pointer dereferencing further down the line. Signed-off-by: Alexander Barabash <alexander.barabash@xxxxxxxx> Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx> Link: https://lore.kernel.org/r/75e9c0e84c3345d693c606c64f8b9ab5@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/dma/ioat/dma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c index 49386ce04bf5..1389f0582e29 100644 --- a/drivers/dma/ioat/dma.c +++ b/drivers/dma/ioat/dma.c @@ -394,10 +394,11 @@ ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags) descs->virt = dma_alloc_coherent(to_dev(ioat_chan), SZ_2M, &descs->hw, flags); - if (!descs->virt && (i > 0)) { + if (!descs->virt) { int idx; for (idx = 0; idx < i; idx++) { + descs = &ioat_chan->descs[idx]; dma_free_coherent(to_dev(ioat_chan), SZ_2M, descs->virt, descs->hw); descs->virt = NULL; -- 2.20.1
