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The race > is expected, so read it with READ_ONCE() to match the writer. > > [ 14.915975] BUG: KCSAN: data-race in mm_update_next_owner / try_to_set_owner > > [ 14.916154] write (marked) to 0xff11000004471b80 of 8 bytes by task 71 on cpu 0: > [ 14.916204] try_to_set_owner+0x100/0x140 > [ 14.916302] mm_update_next_owner+0x177/0x300 > ... > > [ 14.917246] read to 0xff11000004471b80 of 8 bytes by task 75 on cpu 1: > [ 14.917293] mm_update_next_owner+0x2a/0x300 > [ 14.917396] do_exit+0x575/0x18b0 > ... > > [ 14.923906] value changed: 0xff1100002ec04180 -> 0xff1100002ed3a0c0 > > Found with KCSAN while fuzzing under a deterministic hypervisor that's > currently under development. > > Signed-off-by: Mani Tofigh > --- > kernel/exit.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/exit.c b/kernel/exit.c > index d5e7bc2af804..cc78596db74d 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -494,7 +494,7 @@ void mm_update_next_owner(struct mm_struct *mm) > * If the exiting or execing task is not the owner, it's > * someone else's problem. > */ > - if (mm->owner != p) > + if (READ_ONCE(mm->owner) != p) > return; > /* > * The current owner is exiting/execing and there are no other > Acked-by: Balbir Singh Balbir