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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-11 06:52:16 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-11 06:52:16 +0300 |
| commit | 223ba8ee0a3986718c874b66ed24e7f87f6b8124 (patch) | |
| tree | 7597b02a3a145b618b19a3e7e4f65875ee3cd68a /include/linux | |
| parent | 7aac71907bdea16e2754a782b9d9155449a9d49d (diff) | |
| parent | 8a68d64bb10334426834e8c273319601878e961e (diff) | |
| download | linux-223ba8ee0a3986718c874b66ed24e7f87f6b8124.tar.xz | |
Merge tag 'vmscape-for-linus-20250904' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull vmescape mitigation fixes from Dave Hansen:
"Mitigate vmscape issue with indirect branch predictor flushes.
vmscape is a vulnerability that essentially takes Spectre-v2 and
attacks host userspace from a guest. It particularly affects
hypervisors like QEMU.
Even if a hypervisor may not have any sensitive data like disk
encryption keys, guest-userspace may be able to attack the
guest-kernel using the hypervisor as a confused deputy.
There are many ways to mitigate vmscape using the existing Spectre-v2
defenses like IBRS variants or the IBPB flushes. This series focuses
solely on IBPB because it works universally across vendors and all
vulnerable processors. Further work doing vendor and model-specific
optimizations can build on top of this if needed / wanted.
Do the normal issue mitigation dance:
- Add the CPU bug boilerplate
- Add a list of vulnerable CPUs
- Use IBPB to flush the branch predictors after running guests"
* tag 'vmscape-for-linus-20250904' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vmscape: Add old Intel CPUs to affected list
x86/vmscape: Warn when STIBP is disabled with SMT
x86/bugs: Move cpu_bugs_smt_update() down
x86/vmscape: Enable the mitigation
x86/vmscape: Add conditional IBPB mitigation
x86/vmscape: Enumerate VMSCAPE bug
Documentation/hw-vuln: Add VMSCAPE documentation
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/cpu.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h index b91b993f58ee..487b3bf2e1ea 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -83,6 +83,7 @@ extern ssize_t cpu_show_old_microcode(struct device *dev, extern ssize_t cpu_show_indirect_target_selection(struct device *dev, struct device_attribute *attr, char *buf); extern ssize_t cpu_show_tsa(struct device *dev, struct device_attribute *attr, char *buf); +extern ssize_t cpu_show_vmscape(struct device *dev, struct device_attribute *attr, char *buf); extern __printf(4, 5) struct device *cpu_device_create(struct device *parent, void *drvdata, |