lkdtm: fix memory leak of base

This case is supposed to read from a memory after it has been freed,
but we missed freeing base if the memory 'val' could not be allocated.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index 2f0b02248761..5b3a63c87ec9 100644
--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -458,8 +458,10 @@ static void lkdtm_do_action(enum ctype which)
                         break;
 
                 val = kmalloc(len, GFP_KERNEL);
-                if (!val)
+                if (!val) {
+                        kfree(base);
                         break;
+                }
 
                 *val = 0x12345678;
                 base[offset] = *val;