From: Jann Horn <jannh@xxxxxxxxxx>
commit 29d6455178a09e1dc340380c582b13356227e8df upstream.
Until now, hitting this BUG_ON caused a recursive oops (because oops
handling involves do_exit(), which calls into the scheduler, which in
turn raises an oops), which caused stuff below the stack to be
overwritten until a panic happened (e.g. via an oops in interrupt
context, caused by the overwritten CPU index in the thread_info).
Just panic directly.
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[AmitP: Minor refactoring of upstream changes for linux-3.18.y]
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
---
kernel/sched/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5f4c71c5d38e..a760c9e0353e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2709,7 +2709,8 @@ static noinline void __schedule_bug(struct task_struct *prev)
static inline void schedule_debug(struct task_struct *prev)
{
#ifdef CONFIG_SCHED_STACK_END_CHECK
- BUG_ON(unlikely(task_stack_end_corrupted(prev)));
+ if (task_stack_end_corrupted(prev))
+ panic("corrupted stack end detected inside scheduler\n");
#endif
/*
* Test if we are atomic. Since do_exit() needs to call into
--
2.7.4