Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Check for invalid/obsolete root *after* making MMU pages available Check for a "stale" page fault, i.e. for an invalid and/or obsolete root, after making MMU pages available for the shadow MMU. If reclaiming shadow pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to map memory into an invalid root. On its own, populating an invalid root is "fine", but because child shadow pages inherit their parent's role, any children created during the map/fetch will be created as invalid pages, thus violating KVM's invariant that invalid pages are never on the list of active MMU pages. Note, the underlying flaw has existed since KVM first started tracking invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root pagetables"), but the true badness only came along in 2020 (Linux 5.9) with the invariant that invalid shadow pages can't be on the list of active pages. Note #2, inheriting role.invalid when creating child shadow pages is also far from ideal; that flaw will be addressed separately.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before 62ef67af1878fa2cd066642f2f59e33ade95f637; affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before 65c4f7a1028cf01a93a2762d679c289810ede990; affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before 35e77467610c4a37cb0ff54ee56b85f73b1f5700; affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before 0026dbb7de8ea76e97d6edf42fc3cc084564e2bf; affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before f3477a6a4164f15287444eda685b5f6405dbd1e5; affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before bce0d3c26e2c761a4bf43c8949f333fc7374eb2d; affected f95eec9bed76d42194c23153cb1cc8f186bf91cb before 2abd5287f08319fa35764566b15c6e22cb1068db |
| Linux / Linux | affected 5.9; unaffected 0 before 5.9; unaffected 5.15.218 through 5.15.*; unaffected 6.1.183 through 6.1.*; unaffected 6.6.148 through 6.6.*; unaffected 6.12.101 through 6.12.*; unaffected 6.18.42 through 6.18.*; unaffected 7.1.6 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/62ef67af1878fa2cd066642f2f59e33ade95f637
- https://git.kernel.org/stable/c/65c4f7a1028cf01a93a2762d679c289810ede990
- https://git.kernel.org/stable/c/35e77467610c4a37cb0ff54ee56b85f73b1f5700
- https://git.kernel.org/stable/c/0026dbb7de8ea76e97d6edf42fc3cc084564e2bf
- https://git.kernel.org/stable/c/f3477a6a4164f15287444eda685b5f6405dbd1e5
- https://git.kernel.org/stable/c/bce0d3c26e2c761a4bf43c8949f333fc7374eb2d
- https://git.kernel.org/stable/c/2abd5287f08319fa35764566b15c6e22cb1068db
- https://github.com/V4bel/Zapscape
ADP enrichment
No English description supplied.
No references supplied.