From mboxrd@z Thu Jan 1 00:00:00 1970 From: mporter@ti.com (Matt Porter) Date: Mon, 4 Mar 2013 11:52:57 -0500 Subject: [PATCH] arm: davinci: fix edma dmaengine induced null pointer dereference on da830 Message-ID: <1362415977-12829-1-git-send-email-mporter@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 at kernel.org --- arch/arm/mach-davinci/dma.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c index a685e97..f9eb836 100644 --- a/arch/arm/mach-davinci/dma.c +++ b/arch/arm/mach-davinci/dma.c @@ -747,6 +747,8 @@ int edma_alloc_slot(unsigned ctlr, int slot) slot = EDMA_CHAN_SLOT(slot); if (slot < 0) { + if (!edma_cc[ctlr]) + return -EINVAL; slot = edma_cc[ctlr]->num_channels; for (;;) { slot = find_next_zero_bit(edma_cc[ctlr]->edma_inuse, -- 1.7.9.5