Local privilege escalation via stale MMIO list entries
Published Feb 29, 2024 · Updated Aug 5, 2026
Use-after-free in the Linux KVM coalesced-MMIO subsystem allows local users with /dev/kvm access to corrupt host kernel memory. When bus reallocation fails, kvm_io_bus_unregister_dev() destroys later devices, but the caller continues iterating coalesced_zones and dereferences deleted list entries. The ioctl path requires local KVM-device access; exploitation can disclose or modify kernel memory, elevate privileges, or panic the host.
Summary
What happened
Use-after-free in the Linux KVM coalesced-MMIO subsystem allows local users with /dev/kvm access to corrupt host kernel memory. When bus reallocation fails, kvm_io_bus_unregister_dev() destroys later devices, but the caller continues iterating coalesced_zones and dereferences deleted list entries. The ioctl path requires local KVM-device access; exploitation can disclose or modify kernel memory, elevate privileges, or panic the host.
The record
- CVE
- CVE-2021-47060
- Published
- Feb 29, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 29, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=19184bd06f488af62924ff1747614a8cb284ad63
- Affected versionversion=40a023f681befd9b2862a3c16fb306a38b359ae5
- Affected versionversion=4.14.200 <4.15
- Affected versionversion=4.19.148 <4.20
- Affected versionversion=41b2ea7a6a11e2b1a7f2c29e1675a709a6b2b98d <7d1bc32d6477ff96a32695ea4be8144e4513ab2d
- Affected versionversion=4.4.238 <4.5
- Affected versionversion=4.9.238 <4.10
- Affected versionversion=5.4.66 <5.4.119
- Affected versionversion=5.8.10 <5.9
- Affected versionversion=5.9
- Affected versionversion=68c125324b5e1d1d22805653735442923d896a1d
- Affected versionversion=840e124f89a5127e7eb97ebf377f4b8ca745c070
- Affected versionversion=f0dfffce3f4ffd5f822568a4a6fb34c010e939d1
- Affected versionversion=f65886606c2d3b562716de030706dfe1bea4ed5e <168e82f640ed1891a700bdb43e37da354b2ab63c
- Affected versionversion=f65886606c2d3b562716de030706dfe1bea4ed5e <2a20592baff59c5351c5200ec667e1a2aa22af85
- Affected versionversion=f65886606c2d3b562716de030706dfe1bea4ed5e <50cbad42bfea8c052b7ca590bd4126cdc898713c
- Affected versionversion=f65886606c2d3b562716de030706dfe1bea4ed5e <5d3c4c79384af06e3c8e25b7770b6247496b4417
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Technologies
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