Messages in this thread | | | Date | Thu, 17 Nov 2016 08:01:50 -0600 | From | Josh Poimboeuf <> | Subject | Re: perf: fuzzer KASAN unwind_get_return_address |
| |
On Thu, Nov 17, 2016 at 10:48:27AM +0100, Dmitry Vyukov wrote: > Just in case, there is currently a known KASAN false positive related > to longjmp's on GPFs. When a syscall hits GPF stack is unwound to > kernel entry point, this leaves a bunch of stray poisoned redzones on > the thread stack. They later cause false stack-out-of-bounds reports. > > But this does not seem to be the case here. Kernel is not tainted. And > shadow at the bottom of the reports looks sane. > > But if that's the case somehow, we will need to add > kasan_unpoison_remaining_stack() call before a longjmp like we did for > jprobe_return(): > https://groups.google.com/d/msg/kasan-dev/Hzox58yZ4MU/TOdFoWMuBQAJ
I'm pretty sure this isn't a KASAN false positive. The unwinder does actually seem to be accessing a bad area of the stack, in the middle of a function's stack frame.
-- Josh
| |