CVE-2023-53082: Vulnerability in Linux Linux

Severity: highType: vulnerabilityCVE-2023-53082

In the Linux kernel, the following vulnerability has been resolved: vp_vdpa: fix the crash in hot unplug with vp_vdpa While unplugging the vp_vdpa device, it triggers a kernel panic The root cause is: vdpa_mgmtdev_unregister() will accesses modern devices which will cause a use after free. So need to change the sequence in vp_vdpa_remove [ 195.003359] BUG: unable to handle page fault for address: ff4e8beb80199014 [ 195.004012] #PF: supervisor read access in kernel mode [ 195.004486] #PF: error_code(0x0000) - not-present page [ 195.004960] PGD 100000067 P4D 1001b6067 PUD 1001b7067 PMD 1001b8067 PTE 0 [ 195.005578] Oops: 0000 1 PREEMPT SMP PTI [ 195.005968] CPU: 13 PID: 164 Comm: kworker/u56:10 Kdump: loaded Not tainted 5.14.0-252.el9.x86_64 #1 [ 195.006792] Hardware name: Red Hat KVM/RHEL, BIOS edk2-20221207gitfff6d81270b5-2.el9 unknown [ 195.007556] Workqueue: kacpi_hotplug acpi_hotplug_work_fn [ 195.008059] RIP: 0010:ioread8+0x31/0x80 [ 195.008418] Code: 77 28 48 81 ff 00 00 01 00 76 0b 89 fa ec 0f b6 c0 c3 cc cc cc cc 8b 15 ad 72 93 01 b8 ff 00 00 00 85 d2 75 0f c3 cc cc cc cc <8a> 07 0f b6 c0 c3 cc cc cc cc 83 ea 01 48 83 ec 08 48 89 fe 48 c7 [ 195.010104] RSP: 0018:ff4e8beb8067bab8 EFLAGS: 00010292 [ 195.010584] RAX: ffffffffc05834a0 RBX: ffffffffc05843c0 RCX: ff4e8beb8067bae0 [ 195.011233] RDX: ff1bcbd580f88000 RSI: 0000000000000246 RDI: ff4e8beb80199014 [ 195.011881] RBP: ff1bcbd587e39000 R08: ffffffff916fa2d0 R09: ff4e8beb8067ba68 [ 195.012527] R10: 000000000000001c R11: 0000000000000000 R12: ff1bcbd5a3de9120 [ 195.013179] R13: ffffffffc062d000 R14: 0000000000000080 R15: ff1bcbe402bc7805 [ 195.013826] FS: 0000000000000000(0000) GS:ff1bcbe402740000(0000) knlGS:0000000000000000 [ 195.014564] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 195.015093] CR2: ff4e8beb80199014 CR3: 0000000107dea002 CR4: 0000000000771ee0 [ 195.015741] PKRU: 55555554 [ 195.016001] Call Trace: [ 195.016233] <TASK> [ 195.016434] vp_modern_get_status+0x12/0x20 [ 195.016823] vp_vdpa_reset+0x1b/0x50 [vp_vdpa] [ 195.017238] virtio_vdpa_reset+0x3c/0x48 [virtio_vdpa] [ 195.017709] remove_vq_common+0x1f/0x3a0 [virtio_net] [ 195.018178] virtnet_remove+0x5d/0x70 [virtio_net] [ 195.018618] virtio_dev_remove+0x3d/0x90 [ 195.018986] device_release_driver_internal+0x1aa/0x230 [ 195.019466] bus_remove_device+0xd8/0x150 [ 195.019841] device_del+0x18b/0x3f0 [ 195.020167] ? kernfs_find_ns+0x35/0xd0 [ 195.020526] device_unregister+0x13/0x60 [ 195.020894] unregister_virtio_device+0x11/0x20 [ 195.021311] device_release_driver_internal+0x1aa/0x230 [ 195.021790] bus_remove_device+0xd8/0x150 [ 195.022162] device_del+0x18b/0x3f0 [ 195.022487] device_unregister+0x13/0x60 [ 195.022852] ? vdpa_dev_remove+0x30/0x30 [vdpa] [ 195.023270] vp_vdpa_dev_del+0x12/0x20 [vp_vdpa] [ 195.023694] vdpa_match_remove+0x2b/0x40 [vdpa] [ 195.024115] bus_for_each_dev+0x78/0xc0 [ 195.024471] vdpa_mgmtdev_unregister+0x65/0x80 [vdpa] [ 195.024937] vp_vdpa_remove+0x23/0x40 [vp_vdpa] [ 195.025353] pci_device_remove+0x36/0xa0 [ 195.025719] device_release_driver_internal+0x1aa/0x230 [ 195.026201] pci_stop_bus_device+0x6c/0x90 [ 195.026580] pci_stop_and_remove_bus_device+0xe/0x20 [ 195.027039] disable_slot+0x49/0x90 [ 195.027366] acpiphp_disable_and_eject_slot+0x15/0x90 [ 195.027832] hotplug_event+0xea/0x210 [ 195.028171] ? hotplug_event+0x210/0x210 [ 195.028535] acpiphp_hotplug_notify+0x22/0x80 [ 195.028942] ? hotplug_event+0x210/0x210 [ 195.029303] acpi_device_hotplug+0x8a/0x1d0 [ 195.029690] acpi_hotplug_work_fn+0x1a/0x30 [ 195.030077] process_one_work+0x1e8/0x3c0 [ 195.030451] worker_thread+0x50/0x3b0 [ 195.030791] ? rescuer_thread+0x3a0/0x3a0 [ 195.031165] kthread+0xd9/0x100 [ 195.031459] ? kthread_complete_and_exit+0x20/0x20 [ 195.031899] ret_from_fork+0x22/0x30 [ 195.032233] </TASK>

AI Analysis

Technical Summary

CVE-2023-53082 is a vulnerability in the Linux kernel related to the vp_vdpa driver, which is part of the vDPA (virtio Data Path Acceleration) framework. The issue arises during the hot unplugging process of a vp_vdpa device, where the kernel triggers a panic due to a use-after-free condition. Specifically, the function vdpa_mgmtdev_unregister() accesses modern devices after they have been freed, causing invalid memory access and a kernel crash. The root cause is an incorrect sequence of operations in the vp_vdpa_remove function, leading to the use-after-free scenario. The kernel panic logs indicate a page fault triggered by supervisor read access to a non-present page, with the call stack showing the sequence of function calls leading to the crash. This vulnerability affects Linux kernel versions containing the vp_vdpa driver implementation prior to the fix, which involves reordering the device removal sequence to prevent access to freed memory. Exploiting this vulnerability requires triggering a hot unplug event on a vp_vdpa device, which could be done by an attacker with sufficient privileges to manipulate device hotplug events or by malicious code running on the host. The vulnerability does not appear to be exploited in the wild yet, and no CVSS score has been assigned. However, the impact is significant as it causes a kernel panic, leading to denial of service (DoS) on affected systems. The vulnerability affects Linux systems using vDPA devices, commonly found in virtualized environments leveraging virtio and KVM/QEMU virtualization stacks.

Potential Impact

For European organizations, the impact of CVE-2023-53082 could be substantial, especially those relying on Linux-based virtualization infrastructure using vDPA devices for network acceleration. The kernel panic caused by this vulnerability results in system crashes, leading to service interruptions and potential downtime. This can affect cloud service providers, data centers, and enterprises running virtualized workloads on Linux hosts. The denial of service could disrupt critical business applications, impact availability of services, and cause operational delays. While the vulnerability does not directly lead to privilege escalation or data breach, the instability and forced reboots could be exploited as part of a broader attack strategy to degrade service reliability. Organizations in sectors such as finance, telecommunications, and public services that depend heavily on virtualized Linux infrastructure may face operational risks. Additionally, the complexity of the vulnerability means that patching requires kernel updates, which may involve planned maintenance windows and testing to avoid unintended disruptions.

Mitigation Recommendations

To mitigate CVE-2023-53082, European organizations should: 1) Apply the latest Linux kernel patches that address the vp_vdpa device removal sequence to prevent use-after-free conditions. Monitor vendor advisories and update kernels promptly, especially on systems running vDPA-enabled virtualization hosts. 2) Limit the ability to perform hot unplug operations on vDPA devices to trusted administrators only, reducing the risk of accidental or malicious triggering of the vulnerability. 3) Implement strict access controls and monitoring on virtualization management interfaces to detect and prevent unauthorized device hotplug/unplug commands. 4) Employ kernel crash dump and monitoring tools to quickly identify and respond to kernel panics related to this vulnerability. 5) Test kernel updates in staging environments to ensure compatibility and stability before deployment in production. 6) Consider isolating critical virtualized workloads from hosts that cannot be immediately patched, using network segmentation and workload migration strategies. 7) Maintain up-to-date backups and disaster recovery plans to minimize downtime impact in case of crashes.