From: Matt Porter Date: Tue, 5 Mar 2013 15:58:22 +0000 (-0500) Subject: ARM: davinci: edma: fix dmaengine induced null pointer dereference on da830 X-Git-Tag: v3.9-rc4~34^2~11^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=069552777a121eb39da29de4bc0383483dbe1f7e;p=linux.git 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 --- 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);