[PATCH 4.14 34/59] pstore/ram: Avoid allocation and leak of platform data

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook@chromium.org>

commit 5631e8576a3caf606cdc375f97425a67983b420c upstream.

Yue Hu noticed that when parsing device tree the allocated platform data
was never freed. Since it's not used beyond the function scope, this
switches to using a stack variable instead.

Reported-by: Yue Hu <huyue2@yulong.com>
Fixes: 35da60941e44 ("pstore/ram: add Device Tree bindings")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/pstore/ram.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -711,18 +711,15 @@ static int ramoops_probe(struct platform
 {
 	struct device *dev = &pdev->dev;
 	struct ramoops_platform_data *pdata = dev->platform_data;
+	struct ramoops_platform_data pdata_local;
 	struct ramoops_context *cxt = &oops_cxt;
 	size_t dump_mem_sz;
 	phys_addr_t paddr;
 	int err = -EINVAL;
 
 	if (dev_of_node(dev) && !pdata) {
-		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
-		if (!pdata) {
-			pr_err("cannot allocate platform data buffer\n");
-			err = -ENOMEM;
-			goto fail_out;
-		}
+		pdata = &pdata_local;
+		memset(pdata, 0, sizeof(*pdata));
 
 		err = ramoops_parse_dt(pdev, pdata);
 		if (err < 0)