The patch below does not apply to the 4.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2f7caf6b02145bd9cd9d0b56204f51a5fefe7790 Mon Sep 17 00:00:00 2001

From: Gilad Ben-Yossef gilad@benyossef.com Date: Sun, 7 Jan 2018 12:14:24 +0000 Subject: [PATCH] staging: ccree: check DMA pool buf !NULL before free

If we ran out of DMA pool buffers, we get into the unmap code path with a NULL before. Deal with this by checking the virtual mapping is not NULL.

Cc: stable@vger.kernel.org Signed-off-by: Gilad Ben-Yossef gilad@benyossef.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/staging/ccree/ssi_buffer_mgr.c b/drivers/staging/ccree/ssi_buffer_mgr.c index e85bb53a3289..78288ed75281 100644 --- a/drivers/staging/ccree/ssi_buffer_mgr.c +++ b/drivers/staging/ccree/ssi_buffer_mgr.c @@ -465,7 +465,8 @@ void cc_unmap_blkcipher_request(struct device *dev, void *ctx, DMA_TO_DEVICE); } /* Release pool */ - if (req_ctx->dma_buf_type == CC_DMA_BUF_MLLI) { + if (req_ctx->dma_buf_type == CC_DMA_BUF_MLLI && + req_ctx->mlli_params.mlli_virt_addr) { dma_pool_free(req_ctx->mlli_params.curr_pool, req_ctx->mlli_params.mlli_virt_addr, req_ctx->mlli_params.mlli_dma_addr);