> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx> > Sent: Tuesday, September 5, 2023 1:24 PM > > Hi Kevin, > > I am trying to address this issue in below patch. Does it looks sane to > you? > > iommu: Consolidate per-device fault data management > > The per-device fault data is a data structure that is used to store > information about faults that occur on a device. This data is allocated > when IOPF is enabled on the device and freed when IOPF is disabled. The > data is used in the paths of iopf reporting, handling, responding, and > draining. > > The fault data is protected by two locks: > > - dev->iommu->lock: This lock is used to protect the allocation and > freeing of the fault data. > - dev->iommu->fault_parameter->lock: This lock is used to protect the > fault data itself. > > Improve the iopf code to enforce this lock mechanism and add a reference > counter in the fault data to avoid use-after-free issue. > Can you elaborate the use-after-free issue and why a new user count is required? btw a Fix tag is required given this mislocking issue has been there for quite some time...
