mmc: cqhci: Fix a tiny potential memory leak on error condition [Linux 5.0]

mmc: cqhci: Fix a tiny potential memory leak on error condition [Linux 5.0]

This Linux kernel change "mmc: cqhci: Fix a tiny potential memory leak on error condition" is included in the Linux 5.0 release. This change is authored by Alamy Liu <alamy.liu [at] gmail.com> on Mon Feb 25 11:22:14 2019 -0800. The commit for this change in Linux stable tree is d07e9fa (patch).

mmc: cqhci: Fix a tiny potential memory leak on error condition

Free up the allocated memory in the case of error return

The value of mmc_host->cqe_enabled stays 'false'. Thus, cqhci_disable
(mmc_cqe_ops->cqe_disable) won't be called to free the memory.  Also,
cqhci_disable() seems to be designed to disable and free all resources, not
suitable to handle this corner case.

Fixes: a4080225f51d ("mmc: cqhci: support for command queue enabled host")
Signed-off-by: Alamy Liu <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: [email protected]
Signed-off-by: Ulf Hansson <[email protected]>

There are 11 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 drivers/mmc/host/cqhci.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/cqhci.c b/drivers/mmc/host/cqhci.c
index bd9a59b..a8af682 100644
--- a/drivers/mmc/host/cqhci.c
+++ b/drivers/mmc/host/cqhci.c
@@ -217,12 +217,21 @@ static int cqhci_host_alloc_tdl(struct cqhci_host *cq_host)
                         cq_host->desc_size,
                         &cq_host->desc_dma_base,
                         GFP_KERNEL);
+   if (!cq_host->desc_base)
+       return -ENOMEM;
+
    cq_host->trans_desc_base = dmam_alloc_coherent(mmc_dev(cq_host->mmc),
                          cq_host->data_size,
                          &cq_host->trans_desc_dma_base,
                          GFP_KERNEL);
-   if (!cq_host->desc_base || !cq_host->trans_desc_base)
+   if (!cq_host->trans_desc_base) {
+       dmam_free_coherent(mmc_dev(cq_host->mmc), cq_host->desc_size,
+                  cq_host->desc_base,
+                  cq_host->desc_dma_base);
+       cq_host->desc_base = NULL;
+       cq_host->desc_dma_base = 0;
        return -ENOMEM;
+   }

    pr_debug("%s: cqhci: desc-base: 0x%p trans-base: 0x%p\n desc_dma 0x%llx trans_dma: 0x%llx\n",
         mmc_hostname(cq_host->mmc), cq_host->desc_base, cq_host->trans_desc_base,

Leave a Reply

Your email address will not be published. Required fields are marked *