pstore/ram: Avoid allocation and leak of platform data

BugLink: https://bugs.launchpad.net/bugs/1837477
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 9c5f8d8c051c35e92a70ca01ebac938ef6947c8f..267932fdd1df61798c5274177b33a82da615f0ae 100644 (file)
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -711,18 +711,15 @@ static int ramoops_probe(struct platform_device *pdev)
 {
        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)