Messages in this thread | | | Subject | Re: [PATCH] x86/entry/64: wipe KASAN stack shadow in rewind_stack_do_exit() | From | Andrey Ryabinin <> | Date | Tue, 28 Aug 2018 14:33:48 +0300 |
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On 08/28/2018 01:38 PM, Jann Horn wrote:
>> >> >> Why this has to be done in the rewind_stack_do_exit()? >> Are there any problems with calling the kasan_unpoison_task_stack(current) from oops_end(), before the rewind_stack_do_exit()? > > Ooh, good point! I didn't see that KASAN instrumentation is disabled > for dumpstack.c.
It doesn't really matter. This would work with instrumented oops_end() as well. kasan_unpoison_task_stack() will unpoison everything including oops_end's stack. It would be also ok if kasan_unpoison_task_stack() instrumented, or calling any number of instrumented functions in between kasan_unpoison_task_stack() and rewind_stack_do_exit(). As long as we return from these functions before the rewind_stack_do_exit(), the stack will be unpoisoned on return.
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