From 069552777a121eb39da29de4bc0383483dbe1f7e Mon Sep 17 00:00:00 2001 From: Matt Porter Date: Tue, 5 Mar 2013 10:58:22 -0500 Subject: [PATCH] ARM: davinci: edma: fix dmaengine induced null pointer dereference on da830 This adds additional error checking to the private edma api implementation to catch the case where the edma_alloc_slot() has an invalid controller parameter. The edma dmaengine wrapper driver relies on this condition being handled in order to avoid setting up a second edma dmaengine instance on DA830. Verfied using a DA850 with the second EDMA controller platform instance removed to simulate a DA830 which only has a single EDMA controller. Reported-by: Tomas Novotny Signed-off-by: Matt Porter Cc: stable@vger.kernel.org # v3.7.x+ Tested-by: Tomas Novotny Signed-off-by: Sekhar Nori --- arch/arm/mach-davinci/dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c index a685e9706b7b..45b7c71d9cc1 100644 --- a/arch/arm/mach-davinci/dma.c +++ b/arch/arm/mach-davinci/dma.c @@ -743,6 +743,9 @@ EXPORT_SYMBOL(edma_free_channel); */ int edma_alloc_slot(unsigned ctlr, int slot) { + if (!edma_cc[ctlr]) + return -EINVAL; + if (slot >= 0) slot = EDMA_CHAN_SLOT(slot); -- 2.20.1