From: Chen Ridong <chenridong@xxxxxxxxxx> The at_xdmac_memset_create_desc may return NULL, which will lead to a null pointer dereference. For example, the len input is error, or the atchan->free_descs_list is empty and memory is exhausted. Therefore, add check to avoid this. Fixes: b206d9a23ac7 ("dmaengine: xdmac: Add memset support") Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx> --- drivers/dma/at_xdmac.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 299396121e6d..e847ad66dc0b 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1363,6 +1363,8 @@ at_xdmac_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, return NULL; desc = at_xdmac_memset_create_desc(chan, atchan, dest, len, value); + if (!desc) + return NULL; list_add_tail(&desc->desc_node, &desc->descs_list); desc->tx_dma_desc.cookie = -EBUSY; -- 2.34.1