Bug 2507280 (CVE-2026-64309)

Summary: CVE-2026-64309 kernel: crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT)
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's `crypto: ccp` module. This vulnerability arises from improper initialization of Secure Nested Paging (SNP) when handling the `ioctl(SNP_COMMIT)` command. A local userspace process can exploit this by sending specific commands via `/dev/sev` ioctls. If Secure Encrypted Virtualization (SEV) initialization fails and Kernel-based Virtual Machine (KVM) is actively running virtual machines, this flaw could lead to a Denial of Service (DoS) by causing a host crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-07-25 10:14:18 UTC
In the Linux kernel, the following vulnerability has been resolved:

crypto: ccp - Do not initialize SNP for ioctl(SNP_COMMIT)

Sashiko notes:

> if SEV initialization fails and KVM is actively running normal VMs, could a
> userspace process trigger this code path via /dev/sev ioctls (e.g.,
> SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN
> execution for an active VM trigger a general protection fault and crash the
> host?

The SNP_COMMIT command does not require the firmware to be in any
particular state. Skip initializing it if it was previously uninitialized.

The SEV-SNP firmware specification doc 56860 does not mention SNP_COMMIT in
Table 5 as a command that is allowed in the UNINIT state, but it is in fact
allowed and a future documentation update will reflect that.