[3.18,52/59] stackprotector: Increase the per-task stack canarys random range from 32 bits to 64 bits on 64-bit platforms

Commit Message

Greg Kroah-Hartman May 23, 2017, 8:10 p.m. UTC

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Daniel Micay <[e-mail]>

commit 5ea30e4e58040cfd6434c2f33dc3ea76e2c15b05 upstream.

The stack canary is an 'unsigned long' and should be fully initialized to
random data rather than only 32 bits of random data.

Signed-off-by: Daniel Micay <[e-mail]>
Acked-by: Arjan van de Ven <[e-mail]>
Acked-by: Rik van Riel <[e-mail]>
Acked-by: Kees Cook <[e-mail]>
Cc: Arjan van Ven <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

---
 kernel/fork.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -338,7 +338,7 @@  static struct task_struct *dup_task_stru
 	set_task_stack_end_magic(tsk);
 
 #ifdef CONFIG_CC_STACKPROTECTOR
-	tsk->stack_canary = get_random_int();
+	tsk->stack_canary = get_random_long();
 #endif
 
 	/*