linux-kernel - [PATCH 1/3] lkdtm: fix false positive warning from -Wmaybe-uninitialized

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1470432353-4297-2-git-send-email-keescook@chromium.org>
Date:	Fri,  5 Aug 2016 14:25:51 -0700
From:	Kees Cook <keescook@...omium.org>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Kees Cook <keescook@...omium.org>, linux-kernel@...r.kernel.org,
	Arnd Bergmann <arnd@...db.de>,
	Michael Ellerman <mpe@...erman.id.au>
Subject: [PATCH 1/3] lkdtm: fix false positive warning from -Wmaybe-uninitialized

The variable in use here doesn't matter (it's just used to exercise taking
up stack space), but this changes its use to pass its address instead,
to avoid a compiler warning:

drivers/misc/lkdtm_usercopy.c:54:15: warning: 'bad_stack' may be used uninitialized in this function [-Wmaybe-uninitialized]

Reported-by: Arnd Bergmann <arnd@...db.de>
Signed-off-by: Kees Cook <keescook@...omium.org>
---
 drivers/misc/lkdtm_usercopy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/lkdtm_usercopy.c b/drivers/misc/lkdtm_usercopy.c
index 5a3fd76eec27..5525a204db93 100644
--- a/drivers/misc/lkdtm_usercopy.c
+++ b/drivers/misc/lkdtm_usercopy.c
@@ -49,7 +49,7 @@ static noinline void do_usercopy_stack(bool to_user, bool bad_frame)
 
 	/* This is a pointer to outside our current stack frame. */
 	if (bad_frame) {
-		bad_stack = do_usercopy_stack_callee((uintptr_t)bad_stack);
+		bad_stack = do_usercopy_stack_callee((uintptr_t)&bad_stack);
 	} else {
 		/* Put start address just inside stack. */
 		bad_stack = task_stack_page(current) + THREAD_SIZE;
-- 
2.7.4