pstore: use memdup_user

Use memdup_user() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 96fbff7b87c8f202b8edeb726a9d9bfac2b889ee..1b6e0ff6bff5e498f851b42f744f9275ada957d9 100644 (file)
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -653,19 +653,16 @@ static int pstore_write_user_compat(struct pstore_record *record,
        if (record->buf)
                return -EINVAL;
 
-       record->buf = kmalloc(record->size, GFP_KERNEL);
-       if (!record->buf)
-               return -ENOMEM;
-
-       if (unlikely(copy_from_user(record->buf, buf, record->size))) {
-               ret = -EFAULT;
+       record->buf = memdup_user(buf, record->size);
+       if (unlikely(IS_ERR(record->buf))) {
+               ret = PTR_ERR(record->buf);
                goto out;
        }
 
        ret = record->psi->write(record);
 
-out:
        kfree(record->buf);
+out:
        record->buf = NULL;
 
        return unlikely(ret < 0) ? ret : record->size;