Messages in this thread Patch in this message | | | From | Aaron Tomlin <> | Subject | [PATCH 2/2] sched: BUG when stack end location is over written | Date | Thu, 4 Sep 2014 15:50:24 +0100 |
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Currently in the event of a stack overrun a call to schedule() does not check for this type of corruption. This corruption is often silent and can go unnoticed. However once the corrupted region is examined at a later stage, the outcome is undefined and often results in a sporadic page fault which cannot be handled.
This patch checks for a stack overrun and takes appropriate action since the damage is already done, there is no point in continuing.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com> --- kernel/sched/core.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ec1a286..d6af6a0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2660,6 +2660,9 @@ static noinline void __schedule_bug(struct task_struct *prev) */ static inline void schedule_debug(struct task_struct *prev) { + if (unlikely(prev != &init_task && + task_stack_end_corrupted(prev))) + BUG(); /* * Test if we are atomic. Since do_exit() needs to call into * schedule() atomically, we ignore that path. Otherwise whine -- 1.9.3
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