| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-56669: iommu/vt-d: Remove cache tags before disabling ATS |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| iommu/vt-d: Remove cache tags before disabling ATS |
| |
| The 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 even |
| after the domain is freed, causing a use-after-free condition. |
| |
| This issue really shows up when multiple VFs from different PFs |
| passed through to a single user-space process via vfio-pci. In such |
| cases, 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 fix |
| it. |
| |
| The Linux kernel CVE team has assigned CVE-2024-56669 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.10 with commit 3b1d9e2b2d6856eabf5faa12d20c97fef657999f and fixed in 6.12.6 with commit 9a0a72d3ed919ebe6491f527630998be053151d8 |
| Issue introduced in 6.10 with commit 3b1d9e2b2d6856eabf5faa12d20c97fef657999f and fixed in 6.13 with commit 1f2557e08a617a4b5e92a48a1a9a6f86621def18 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-56669 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/iommu/intel/iommu.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/9a0a72d3ed919ebe6491f527630998be053151d8 |
| https://git.kernel.org/stable/c/1f2557e08a617a4b5e92a48a1a9a6f86621def18 |
