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TI-2021-21725 Aliases CVE-2021-47060GHSA-6x38-gwgp-2pcm

KVM: Stop looking for coalesced MMIO zones if the bus is destroyed

Priority LOW 34Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: Stop looking for coalesced MMIO zones if the bus is destroyed Abort the walk of coalesced MMIO zones if kvm_io_bus_unregister_dev() fails to allocate memory for the new instance of the bus. If it can't instantiate a new bus, unregister_dev() destroys all devices _except_ the target device. But, it doesn't tell the caller that it obliterated the bus and invoked the destructor for all devices that were on the bus. In the coalesced MMIO case, this can result in a deleted list entry dereference due to attempting to continue iterating on coalesced_zones after future entries (in the walk) have been deleted. Opportunistically add curly braces to the for-loop, which encompasses many lines but sneaks by without braces due to the guts being a single if statement.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0024 15th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.119, 4.5, 4.10 +7Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.4.66 to before 5.4.119; 4.4.238 to before 4.5; 4.9.238 to before 4.10; 4.14.200 to before 4.15; 4.19.148 to before 4.20; 5.8.10 to before 5.95.4.119, 4.5, 4.10, 4.15, 4.20, 5.9Patch availableCNA
LinuxLinux5.9 and later5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13Patch availableCNA
  • Linux VendorLinux Affected 5.4.66 to before 5.4.119; 4.4.238 to before 4.5; 4.9.238 to before 4.10; 4.14.200 to before 4.15; 4.19.148 to before 4.20; 5.8.10 to before 5.9 Fixed in 5.4.119, 4.5, 4.10, 4.15, 4.20, 5.9 Patch available CNA
  • Linux VendorLinux Affected 5.9 and later Fixed in 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.4.66 to before 5.4.119; 5.9 to before 5.10.37; 5.11 to before 5.11.21; 5.12 to before 5.12.4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.4.66 to before 5.4.119; 5.9 to before 5.10.37; 5.11 to before 5.11.21; 5.12 to before 5.12.4 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.4.119, 4.5, 4.10, 4.15, 4.20, 5.9
  • Fix · CNA Linux (Linux) Fixed in 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Not affected: 2 products
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-47060
  2. 2026-10-03 Alias added: GHSA-6x38-gwgp-2pcm

References

Patch 5

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences