Kirill, > diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c > index feeb935a2299..abc096a68f05 100644 > --- a/lib/strnlen_user.c > +++ b/lib/strnlen_user.c > @@ -97,7 +97,7 @@ long strnlen_user(const char __user *str, long count) > return 0; > > max_addr = TASK_SIZE_MAX; > - src_addr = (unsigned long)untagged_addr(str); > + src_addr = (unsigned long)untagged_addr(current->mm, str); In a downstream kernel with LAM disabled I'm seeing current->mm being NULL at this point, because strnlen_user() is being called by kdevtmpfs. IIUC current->mm is only guaranteed to be non-NULL in the userspace process context, whereas untagged_addr() may get called in random places. Am I missing something? -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Liana Sebastian Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
