In the Linux kernel, the following vulnerability has been resolved: x86/vmscape: Add conditional IBPB mitigation VMSCAPE is a vulnerability that exploits insufficient branch predictor isolation between a guest and a userspace hypervisor (like QEMU). Existing mitigations already protect kernel/KVM from a malicious guest. Userspace can additionally be protected by flushing the branch predictors after a VMexit. Since it is the userspace that consumes the poisoned branch predictors, conditionally issue an IBPB after a VMexit and before returning to userspace. Workloads that frequently switch between hypervisor and userspace will incur the most overhead from the new IBPB. This new IBPB is not integrated with the existing IBPB sites. For instance, a task can use the existing speculation control prctl() to get an IBPB at context switch time. With this implementation, the IBPB is doubled up: one at context switch and another before running userspace. The intent is to integrate and optimize these cases post-embargo. [ dhansen: elaborate on suboptimal IBPB solution ]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
NVD-CWE-noinfo
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| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24247d6e00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24246b9bc0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24246b9840> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d242460a6c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2424737640> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d2424735880> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d242460af00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24246bb7c0> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x7d23a5987380> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x7d2424735bc0> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x7d2424608080> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x7d242460bd00> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x7d242460adc0> | Operating System |
| debian | debian_linux | 11.0 | <built-in method update of dict object at 0x7d2424609c80> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |