>>> @@ -2497,6 +2533,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, >>> if (!addr) >>> return NULL; >>> >>> + if (kasan_populate_vmalloc(real_size, area)) >>> + return NULL; >>> + >> >> KASAN itself uses __vmalloc_node_range() to allocate and map shadow in memory online callback. >> So we should either skip non-vmalloc and non-module addresses here or teach kasan's memory online/offline >> callbacks to not use __vmalloc_node_range() (do something similar to kasan_populate_vmalloc() perhaps?). > > Ah, right you are. I haven't been testing that. > > I am a bit nervous about further restricting kasan_populate_vmalloc: I > seem to remember having problems with code using the vmalloc family of > functions to map memory that doesn't lie within vmalloc space but which > still has instrumented accesses. I was wrong or remembering early implementation bugs. If the memory we're allocating in __vmalloc_node_range falls outside of vmalloc and module space, it shouldn't be getting shadow mapped for it by kasan_populate_vmalloc. For v9, I've guarded the call with is_vmalloc_or_module. It seems to work fine when tested with hotplugged memory. Thanks again. Regards, Daniel > On the other hand, I'm not keen on rewriting any of the memory > on/offline code if I can avoid it! > > I'll have a look and get back you as soon as I can. > > Thanks for catching this. > > Kind regards, > Daniel > >> >> -- >> You received this message because you are subscribed to the Google Groups "kasan-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@xxxxxxxxxxxxxxxx. >> To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/352cb4fa-2e57-7e3b-23af-898e113bbe22%40virtuozzo.com.
