From: Thomas Petazzoni Date: Fri, 5 May 2017 09:57:44 +0000 (+0200) Subject: dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly X-Git-Tag: v4.11.5~92 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fdcadb5f70c7666d3f1751e4760791b3162280a5;p=thirdparty%2Fkernel%2Fstable.git dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly commit eb8df543e444492328f506adffc7dfe94111f1bd upstream. The mv_xor_v2_prep_sw_desc() is called from a few different places in the driver, but we never take into account the fact that it might return NULL. This commit fixes that, ensuring that we don't panic if there are no more descriptors available. Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver") Signed-off-by: Thomas Petazzoni Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c index a28a01fcba674..e9280207ac19b 100644 --- a/drivers/dma/mv_xor_v2.c +++ b/drivers/dma/mv_xor_v2.c @@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, __func__, len, &src, &dest, flags); sw_desc = mv_xor_v2_prep_sw_desc(xor_dev); + if (!sw_desc) + return NULL; sw_desc->async_tx.flags = flags; @@ -443,6 +445,8 @@ mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src, __func__, src_cnt, len, &dest, flags); sw_desc = mv_xor_v2_prep_sw_desc(xor_dev); + if (!sw_desc) + return NULL; sw_desc->async_tx.flags = flags; @@ -491,6 +495,8 @@ mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags) container_of(chan, struct mv_xor_v2_device, dmachan); sw_desc = mv_xor_v2_prep_sw_desc(xor_dev); + if (!sw_desc) + return NULL; /* set the HW descriptor */ hw_descriptor = &sw_desc->hw_desc;