From patchwork Thu May 25 17:04:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v2] mmc: bcm2835: fix potential null pointer dereferences From: "Gustavo A. R. Silva" X-Patchwork-Id: 9748761 Message-Id: <20170525170455.GA6904@embeddedgus> To: Stefan Wahren , Ulf Hansson , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, Eric Anholt Cc: "Gustavo A. R. Silva" , linux-mmc@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 25 May 2017 12:04:55 -0500 Null check at line 1165: if (mrq->cmd), implies that mrq->cmd might be NULL. Add null checks before dereferencing pointer mrq->cmd in order to avoid any potential NULL pointer dereference. Addresses-Coverity-ID: 1408740 Tested-by: Stefan Wahren Signed-off-by: Gustavo A. R. Silva --- Changes in v2: Change subject to make it clear the patch is bcm2835 related. drivers/mmc/host/bcm2835.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c index 1f343a4..abba9a2 100644 --- a/drivers/mmc/host/bcm2835.c +++ b/drivers/mmc/host/bcm2835.c @@ -1172,7 +1172,10 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) if (mrq->data && !is_power_of_2(mrq->data->blksz)) { dev_err(dev, "unsupported block size (%d bytes)\n", mrq->data->blksz); - mrq->cmd->error = -EINVAL; + + if (mrq->cmd) + mrq->cmd->error = -EINVAL; + mmc_request_done(mmc, mrq); return; } @@ -1194,7 +1197,10 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK, edm); bcm2835_dumpregs(host); - mrq->cmd->error = -EILSEQ; + + if (mrq->cmd) + mrq->cmd->error = -EILSEQ; + bcm2835_finish_request(host); mutex_unlock(&host->mutex); return; @@ -1207,7 +1213,7 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) if (!host->use_busy) bcm2835_finish_command(host); } - } else if (bcm2835_send_command(host, mrq->cmd)) { + } else if (mrq->cmd && bcm2835_send_command(host, mrq->cmd)) { if (host->data && host->dma_desc) { /* DMA transfer starts now, PIO starts after irq */ bcm2835_start_dma(host);