Bjorn Helgaas <helgaas@xxxxxxxxxx> writes: > On Sat, Aug 03, 2024 at 12:03:25AM +0530, Amit Machhiwal wrote: >> With CONFIG_PCI_DYNAMIC_OF_NODES [1], a hot-plug and hot-unplug sequence >> of a PCI device attached to a PCI-bridge causes following kernel Oops on >> a pseries KVM guest: > > What is unique about pseries here? There's nothing specific to > pseries in the patch, so I would expect this to be a generic problem > on any arch. > >> RTAS: event: 2, Type: Hotplug Event (229), Severity: 1 >> Kernel attempted to read user page (10ec00000048) - exploit attempt? (uid: 0) >> BUG: Unable to handle kernel data access on read at 0x10ec00000048 > > Weird address. I would expect NULL or something. Where did this > non-NULL pointer come from? It originally comes from np->data, which is supposed to be an of_changeset. The powerpc code also uses np->data for the struct pci_dn pointer, see pci_add_device_node_info(). I wonder if that's why it's non-NULL? Amit, do we have exact steps to reproduce this? I poked around a bit but couldn't get it to trigger. cheers
