vfio/pci: Create persistent INTx handler
stable inclusion from stable-v5.15.154 commit 4cb0d7532126d23145329826c38054b4e9a05e7c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9E6TE CVE: CVE-2024-26812 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4cb0d7532126d23145329826c38054b4e9a05e7c -------------------------------- [ Upstream commit 18c198c96a815c962adc2b9b77909eec0be7df4d ] A vulnerability exists where the eventfd for INTx signaling can be deconfigured, which unregisters the IRQ handler but still allows eventfds to be signaled with a NULL context through the SET_IRQS ioctl or through unmask irqfd if the device interrupt is pending. Ideally this could be solved with some additional locking; the igate mutex serializes the ioctl and config space accesses, and the interrupt handler is unregistered relative to the trigger, but the irqfd path runs asynchronous to those. The igate mutex cannot be acquired from the atomic context of the eventfd wake function. Disabling the irqfd relative to the eventfd registration is potentially incompatible with existing userspace. As a result, the solution implemented here moves configuration of the INTx interrupt handler to track the lifetime of the INTx context object and irq_type configuration, rather than registration of a particular trigger eventfd. Synchronization is added between the ioctl path and eventfd_signal() wrapper such that the eventfd trigger can be dynamically updated relative to in-flight interrupts or irqfd callbacks. Cc: <stable@vger.kernel.org> Fixes: 89e1f7d4 ("vfio: Add PCI device driver") Reported-by:Reinette Chatre <reinette.chatre@intel.com> Reviewed-by:
Loading
Please sign in to comment