Time-of-check Time-of-use (TOCTOU) Affecting kernel-debug package, versions *
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Test your applications- Snyk ID SNYK-RHEL8-KERNELDEBUG-1569814
- published 26 Aug 2021
- disclosed 31 Mar 2021
Introduced: 31 Mar 2021
CVE-2021-29657 Open this link in a new tabHow to fix?
There is no fixed version for RHEL:8 kernel-debug.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-debug package and not the kernel-debug package as distributed by RHEL.
See How to fix? for RHEL:8 relevant fixed versions and status.
arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.
References
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134
- https://security.netapp.com/advisory/ntap-20210902-0008/
- https://access.redhat.com/security/cve/CVE-2021-29657
- http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html
- https://bugs.chromium.org/p/project-zero/issues/detail?id=2177