| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 49/75] sched: panic on corrupted stack end | Date | Wed, 22 Jun 2016 15:41:11 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jann Horn <jannh@google.com>
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@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/sched/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3008,7 +3008,8 @@ static noinline void __schedule_bug(stru static inline void schedule_debug(struct task_struct *prev) { #ifdef CONFIG_SCHED_STACK_END_CHECK - BUG_ON(task_stack_end_corrupted(prev)); + if (task_stack_end_corrupted(prev)) + panic("corrupted stack end detected inside scheduler\n"); #endif if (unlikely(in_atomic_preempt_off())) {
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