In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix NULL domain on device release In the kdump kernel, the IOMMU operates in deferredattach mode. In this mode, info->domain may not yet be assigned by the time the releasedevice function is called. It leads to the following crash in the crash kernel: BUG: kernel NULL pointer dereference, address: 000000000000003c ... RIP: 0010:dorawspinlock+0xa/0xa0 ... _rawspinlockirqsave+0x1b/0x30 inteliommureleasedevice+0x96/0x170 iommudeinitdevice+0x39/0xf0 _iommugroupremovedevice+0xa0/0xd0 iommubusnotifier+0x55/0xb0 notifiercallchain+0x5a/0xd0 blockingnotifiercallchain+0x41/0x60 busnotify+0x34/0x50 devicedel+0x269/0x3d0 pciremovebusdevice+0x77/0x100 p2sbbar+0xae/0x1d0 ... i801probe+0x423/0x740 Use the releasedomain mechanism to fix it. The scalable mode context entry which is not part of release domain should be cleared in release_device().