CVE-2024-53214 vfio/pci: Properly hide first-in-list PCIe extended capability

What is CVE-2024-53214?

CVE-2024-53214 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

vfio/pci: Properly hide first-in-list PCIe extended capability

There are cases where a PCIe extended capability should be hidden from the user. For example, an unknown capability (i.e., capability with ID greater than PCI_EXT_CAP_ID_MAX) or a capability that is intentionally chosen to be hidden from the user.

Hiding a capability is done by virtualizing and modifying the 'Next Capability Offset' field of the previous capability so it points to the capability after the one that should be hidden.

The special case where the first capability in the list should be hidden is handled differently because there is no previous capability that can be modified. In this case, the capability ID and version are zeroed while leaving the next pointer intact. This hides the capability and leaves an anchor for the rest of the capability list.

However, today, hiding the first capability in the list is not done properly if the capability is unknown, as struct vfio_pci_core_device->pci_config_map is set to the capability ID during initialization but the capability ID is not properly checked later when used in vfio_config_do_rw(). This leads to the following warning [1] and to an out-of-bounds access to ecap_perms array.

Fix it by checking cap_id in vfio_config_do_rw(), and if it is greater than PCI_EXT_CAP_ID_MAX, use an alternative struct perm_bits for direct read only access instead of the ecap_perms array.

Note that this is safe since the above is the only case where cap_id can exceed PCI_EXT_CAP_ID_MAX (except for the special capabilities, which are already checked before).

[1]

WARNING: CPU: 118 PID: 5329 at drivers/vfio/pci/vfio_pci_config.c:1900 vfio_pci_config_rw+0x395/0x430 [vfio_pci_core] CPU: 118 UID: 0 PID: 5329 Comm: simx-qemu-syste Not tainted 6.12.0+ #1 (snip) Call Trace: <TASK> ? show_regs+0x69/0x80 ? __warn+0x8d/0x140 ? vfio_pci_config_rw+0x395/0x430 [vfio_pci_core] ? report_bug+0x18f/0x1a0 ? handle_bug+0x63/0xa0 ? exc_invalid_op+0x19/0x70 ? asm_exc_invalid_op+0x1b/0x20 ? vfio_pci_config_rw+0x395/0x430 [vfio_pci_core] ? vfio_pci_config_rw+0x244/0x430 [vfio_pci_core] vfio_pci_rw+0x101/0x1b0 [vfio_pci_core] vfio_pci_core_read+0x1d/0x30 [vfio_pci_core] vfio_device_fops_read+0x27/0x40 [vfio] vfs_read+0xbd/0x340 ? vfio_device_fops_unl_ioctl+0xbb/0x740 [vfio] ? __rseq_handle_notify_resume+0xa4/0x4b0 __x64_sys_pread64+0x96/0xc0 x64_sys_call+0x1c3d/0x20d0 do_syscall_64+0x4d/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Weakness: CWE-129

Which versions are affected by CVE-2024-53214?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-53214?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2024-53214 being exploited?

There is no known exploitation of CVE-2024-53214 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2024-53214, DEBIAN-CVE-2024-53214, GHSA-4rwh-4cv9-9p66, UBUNTU-CVE-2024-53214.