This is a note to let you know that I've just added the patch titled
lkdtm: isolate stack corruption test
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 629c66a22c21b692b6e58b9c1d8fa56a60ccb52d Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Thu, 24 Oct 2013 18:05:42 -0700
Subject: lkdtm: isolate stack corruption test
When tests were added to lkdtm that grew the stack frame, the stack
corruption test stopped working. This isolates the test in its own
function, and forces it not to be inlined.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Fixes: cc33c537c12f ("lkdtm: add "EXEC_*" triggers")
Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.12
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/lkdtm.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index 2fc0586..9cbd037 100644
--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -297,6 +297,14 @@ static void do_nothing(void)
return;
}
+static noinline void corrupt_stack(void)
+{
+ /* Use default char array length that triggers stack protection. */
+ char data[8];
+
+ memset((void *)data, 0, 64);
+}
+
static void execute_location(void *dst)
{
void (*func)(void) = dst;
@@ -327,13 +335,9 @@ static void lkdtm_do_action(enum ctype which)
case CT_OVERFLOW:
(void) recursive_loop(0);
break;
- case CT_CORRUPT_STACK: {
- /* Make sure the compiler creates and uses an 8 char array. */
- volatile char data[8];
-
- memset((void *)data, 0, 64);
+ case CT_CORRUPT_STACK:
+ corrupt_stack();
break;
- }
case CT_UNALIGNED_LOAD_STORE_WRITE: {
static u8 data[5] __attribute__((aligned(4))) = {1, 2,
3, 4, 5};
--
1.8.4.6.g82e253f.dirty
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