On Thu, 21 Apr 2022 09:21:06 +1000 Alistair Popple <apopple@xxxxxxxxxx> wrote: > >> As the wait_event() condition is true it will return immediately. This > >> can lead to use-after-free type errors if the caller frees the data > >> structure containing the interval notifier subscription while it is > >> still on a deferred list. Fix this by taking the appropriate lock when > >> reading invalidate_seq to ensure proper synchronisation. > >> > >> ... > >> > >> Fixes: 99cb252f5e68 ("mm/mmu_notifier: add an interval tree notifier") > > > > Do you think fix this should be backported into older kernels? > > Yes, I forgot to cc stable sorry. So we have actually seen these use-after-free errors? Some description of the end-user visible impact is always helpful when deciding which trees need a patch. > Do you want me to resend with > 'Cc: stable@xxxxxxxxxxxxxxx'? Thanks, I added that.