stackprotector: Increase the per-task stack canary's random range from 32 bits to...

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 <danielmicay@gmail.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Arjan van Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170504133209.3053-1-danielmicay@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index 3a4343c..d681f8f 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -536,7 +536,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
        set_task_stack_end_magic(tsk);
 
 #ifdef CONFIG_CC_STACKPROTECTOR
-       tsk->stack_canary = get_random_int();
+       tsk->stack_canary = get_random_long();
 #endif
 
        /*