cve/2024/CVE-2024-56669.md

### [CVE-2024-56669](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-56669)
![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=3b1d9e2b2d6856eabf5faa12d20c97fef657999f%3C%209a0a72d3ed919ebe6491f527630998be053151d8%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

In the Linux kernel, the following vulnerability has been resolved:iommu/vt-d: Remove cache tags before disabling ATSThe current implementation removes cache tags after disabling ATS,leading to potential memory leaks and kernel crashes. Specifically,CACHE_TAG_DEVTLB type cache tags may still remain in the list evenafter the domain is freed, causing a use-after-free condition.This issue really shows up when multiple VFs from different PFspassed through to a single user-space process via vfio-pci. In suchcases, the kernel may crash with kernel messages like: BUG: kernel NULL pointer dereference, address: 0000000000000014 PGD 19036a067 P4D 1940a3067 PUD 136c9b067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 74 UID: 0 PID: 3183 Comm: testCli Not tainted 6.11.9 #2 RIP: 0010:cache_tag_flush_range+0x9b/0x250 Call Trace:  <TASK>  ? __die+0x1f/0x60  ? page_fault_oops+0x163/0x590  ? exc_page_fault+0x72/0x190  ? asm_exc_page_fault+0x22/0x30  ? cache_tag_flush_range+0x9b/0x250  ? cache_tag_flush_range+0x5d/0x250  intel_iommu_tlb_sync+0x29/0x40  intel_iommu_unmap_pages+0xfe/0x160  __iommu_unmap+0xd8/0x1a0  vfio_unmap_unpin+0x182/0x340 [vfio_iommu_type1]  vfio_remove_dma+0x2a/0xb0 [vfio_iommu_type1]  vfio_iommu_type1_ioctl+0xafa/0x18e0 [vfio_iommu_type1]Move cache_tag_unassign_domain() before iommu_disable_pci_caps() to fixit.

### POC

#### Reference
No PoCs from references.

#### Github
- https://github.com/cku-heise/euvd-api-doc