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
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x702b70374180> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bfc2a5540> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bcc9b1040> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bcc9b3080> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bfc130980> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bfc130700> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702bde166100> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x702b703779c0> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x702b703751c0> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x702bfc1327c0> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x702bdc3e8040> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x702bfc2a4f40> | Operating System |
| linux | linux_kernel | 6.17 | <built-in method update of dict object at 0x702b70375a00> | Operating System |
| debian | debian_linux | 11.0 | <built-in method update of dict object at 0x702bdc6a4300> | 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:*:*:*:*:*:*:* |