In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Ignore -EBUSY when checking nested events from vcpu_block()
Ignore -EBUSY when checking nested events after exiting a blocking state
while L2 is active, as exiting to userspace will generate a spurious
userspace exit, usually with KVM_EXIT_UNKNOWN, and likely lead to the VM's
demise. Continuing with the wakeup isn't perfect either, as *something*
has gone sideways if a vCPU is awakened in L2 with an injected event (or
worse, a nested run pending), but continuing on gives the VM a decent
chance of surviving without any major side effects.
As explained in the Fixes commits, it _should_ be impossible for a vCPU to
be put into a blocking state with an already-injected event (exception,
IRQ, or NMI). Unfortunately, userspace can stuff MP_STATE and/or injected
events, and thus put the vCPU into what should be an impossible state.
Don't bother trying to preserve the WARN, e.g. with an anti-syzkaller
Kconfig, as WARNs can (hopefully) be added in paths where _KVM_ would be
violating x86 architecture, e.g. by WARNing if KVM attempts to inject an
exception or interrupt while the vCPU isn't running.
References
Configurations
Configuration 1 (hide)
|
History
08 May 2026, 20:33
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CWE | NVD-CWE-noinfo | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| References | () https://git.kernel.org/stable/c/1c957773063ed3264953597e32990a748381caf6 - Patch | |
| References | () https://git.kernel.org/stable/c/1e88b5f854bdb469424132e0bb44793ad7a7c20a - Patch | |
| References | () https://git.kernel.org/stable/c/2657439265d34a911886b916ba8be97ecc117d51 - Patch | |
| References | () https://git.kernel.org/stable/c/78265cd066d73a5cb41c088fcae4a2515e480d97 - Patch | |
| References | () https://git.kernel.org/stable/c/ead63640d4e72e6f6d464f4e31f7fecb79af8869 - Patch | |
| References | () https://git.kernel.org/stable/c/ec3be7dc9391085a2d96700e159d66d1328b7ff6 - Patch |
06 May 2026, 12:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-06 12:16
Updated : 2026-05-08 20:33
NVD link : CVE-2026-43265
Mitre link : CVE-2026-43265
CVE.ORG link : CVE-2026-43265
JSON object : View
Products Affected
linux
- linux_kernel
CWE