mmc: core: Fix NULL ptr crash from mmc_should_fail_request

commit e5723f95d6b493dd437f1199cacb41459713b32f upstream.

In case of CQHCI, mrq->cmd may be NULL for data requests (non DCMD).
In such case mmc_should_fail_request is directly dereferencing
mrq->cmd while cmd is NULL.
Fix this by checking for mrq->cmd pointer.

Fixes: 72a5af554df8 ("mmc: core: Add support for handling CQE requests")
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 50a5c34..d4f9bfb 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -95,7 +95,7 @@ static void mmc_should_fail_request(struct mmc_host *host,
        if (!data)
                return;
 
-       if (cmd->error || data->error ||
+       if ((cmd && cmd->error) || data->error ||
            !should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
                return;