[PATCH v1 1/2] ACPI: NFIT: Fix memory leak, and local use of devm_*()

[Michal Wilczynski]

devm_*() family of functions purpose is managing memory attached to a
device. So in general it should only be used for allocations that should
last for the whole lifecycle of the device. This is not the case for
acpi_nfit_init_interleave_set(). There are two allocations that are only
used locally in this function. What's more - if the function exits on
error path memory is never freed. It's still attached to dev and would
be freed on device detach, so this leak could be called a 'local leak'.

Fix this by switching from devm_kcalloc() to kcalloc(), and adding
proper rollback.

Fixes: eaf961536e16 ("libnvdimm, nfit: add interleave-set state-tracking 
infrastructure")
Reported-by: Andy Shevchenko <andy.shevche...@gmail.com>
Signed-off-by: Michal Wilczynski <michal.wilczyn...@intel.com>
---
 drivers/acpi/nfit/core.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index f0e6738ae3c9..78f0f855c4de 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2262,6 +2262,7 @@ static int acpi_nfit_init_interleave_set(struct 
acpi_nfit_desc *acpi_desc,
        u16 nr = ndr_desc->num_mappings;
        struct nfit_set_info2 *info2;
        struct nfit_set_info *info;
+       int err = 0;
        int i;
 
        nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL);
@@ -2269,13 +2270,15 @@ static int acpi_nfit_init_interleave_set(struct 
acpi_nfit_desc *acpi_desc,
                return -ENOMEM;
        import_guid(&nd_set->type_guid, spa->range_guid);
 
-       info = devm_kcalloc(dev, nr, sizeof(*info), GFP_KERNEL);
+       info = kcalloc(nr, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;
 
-       info2 = devm_kcalloc(dev, nr, sizeof(*info2), GFP_KERNEL);
-       if (!info2)
-               return -ENOMEM;
+       info2 = kcalloc(nr, sizeof(*info2), GFP_KERNEL);
+       if (!info2) {
+               err = -ENOMEM;
+               goto free_info;
+       }
 
        for (i = 0; i < nr; i++) {
                struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
@@ -2289,7 +2292,8 @@ static int acpi_nfit_init_interleave_set(struct 
acpi_nfit_desc *acpi_desc,
 
                if (!memdev || !nfit_mem->dcr) {
                        dev_err(dev, "%s: failed to find DCR\n", __func__);
-                       return -ENODEV;
+                       err = -ENODEV;
+                       goto free_info2;
                }
 
                map->region_offset = memdev->region_offset;
@@ -2337,10 +2341,13 @@ static int acpi_nfit_init_interleave_set(struct 
acpi_nfit_desc *acpi_desc,
        }
 
        ndr_desc->nd_set = nd_set;
-       devm_kfree(dev, info);
-       devm_kfree(dev, info2);
 
-       return 0;
+free_info2:
+       kfree(info2);
+free_info:
+       kfree(info);
+
+       return err;
 }
 
 static int ars_get_cap(struct acpi_nfit_desc *acpi_desc,
-- 
2.41.0