From 629c66a22c21b692b6e58b9c1d8fa56a60ccb52d Mon Sep 17 00:00:00 2001 From: Kees Cook 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 Fixes: cc33c537c12f ("lkdtm: add "EXEC_*" triggers") Cc: stable # 3.12 Signed-off-by: Greg Kroah-Hartman --- drivers/misc/lkdtm.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'drivers/misc/lkdtm.c') diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c index 2fc0586ce3bb..9cbd0370ca44 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}; -- cgit v1.2.3