CVE-2024-27079

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 deferred_attach mode. In this mode, info->domain may not yet be assigned by the time the release_device function is called. It leads to the following crash in the crash kernel:

BUG: kernel NULL pointer dereference, address: 000000000000003c
...
RIP: 0010:do_raw_spin_lock+0xa/0xa0
...
_raw_spin_lock_irqsave+0x1b/0x30
intel_iommu_release_device+0x96/0x170
iommu_deinit_device+0x39/0xf0
__iommu_group_remove_device+0xa0/0xd0
iommu_bus_notifier+0x55/0xb0
notifier_call_chain+0x5a/0xd0
blocking_notifier_call_chain+0x41/0x60
bus_notify+0x34/0x50
device_del+0x269/0x3d0
pci_remove_bus_device+0x77/0x100
p2sb_bar+0xae/0x1d0
...
i801_probe+0x423/0x740

Use the release_domain mechanism to fix it. The scalable mode context entry which is not part of release domain should be cleared in release_device().

Affected Software

References

• https://git.kernel.org/stable/c/333fe86968482ca701c609af590003bcea450e8f
• https://git.kernel.org/stable/c/81e921fd321614c2ad8ac333b041aae1da7a1c6d