KVM: x86/mmu: make apf token non-zero to fix bug
In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: make apf token non-zero to fix bug In current async pagefault logic, when a page is ready, KVM relies on kvm_arch_can_dequeue_async_page_present() to determine whether to deliver a READY event to the Guest. This function test token value of struct kvm_vcpu_pv_apf_data, which must be reset to zero by Guest kernel when a READY event is finished by Guest. If value is zero meaning that a READY event is done, so the KVM can deliver another. But the kvm_arch_setup_async_pf() may produce a valid token with zero value, which is confused with previous mention and may lead the loss of this READY event. This bug may cause task blocked forever in Guest: INFO: task stress:7532 blocked for more than 1254 seconds. Not tainted 5.10.0 #16 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:stress state:D stack: 0 pid: 7532 ppid: 1409 flags:0x00000080 Call Trace: __schedule+0x1e7/0x650 schedule+0x46/0xb0 kvm_async_pf_task_wait_schedule+0xad/0xe0 ? exit_to_user_mode_prepare+0x60/0x70 __kvm_handle_async_pf+0x4f/0xb0 ? asm_exc_page_fault+0x8/0x30 exc_page_fault+0x6f/0x110 ? asm_exc_page_fault+0x8/0x30 asm_exc_page_fault+0x1e/0x30 RIP: 0033:0x402d00 RSP: 002b:00007ffd31912500 EFLAGS: 00010206 RAX: 0000000000071000 RBX: ffffffffffffffff RCX: 00000000021a32b0 RDX: 000000000007d011 RSI: 000000000007d000 RDI: 00000000021262b0 RBP: 00000000021262b0 R08: 0000000000000003 R09: 0000000000000086 R10: 00000000000000eb R11: 00007fefbdf2baa0 R12: 0000000000000000 R13: 0000000000000002 R14: 000000000007d000 R15: 0000000000001000
- Published
- Aug 22, 2024
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 14th percentile
- CWE
- —
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.8
- CNA · Linux
- 7.1
- 0.7 point gap
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernelbefore 5.10.103
- linux linux kernel5.11 and later · before 5.15.26
- linux linux kernel5.16 and later · before 5.16.12
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 5.8affected
- 2635b5c4a0e407b84f68e188c719f28ba0e9ae1b and later · before 72fdfc75d4217b32363cc80def3de2cb3fef3f02affected · git
- 2635b5c4a0e407b84f68e188c719f28ba0e9ae1b and later · before 4c3644b6c96c5daa5149e5abddc07234eea47c7caffected · git
- 2635b5c4a0e407b84f68e188c719f28ba0e9ae1b and later · before 62040f5cd7d937de547836e747b6aa8212fec573affected · git
- 2635b5c4a0e407b84f68e188c719f28ba0e9ae1b and later · before 6f3c1fc53d86d580d8d6d749c4af23705e4f6f79affected · git
- before 5.8not affected · semver
- 5.10.103 and later · up to and including 5.10.*not affected · semver
- 5.15.26 and later · up to and including 5.15.*not affected · semver
- 5.16.12 and later · up to and including 5.16.*not affected · semver
- 5.17 and laternot affected · original_commit_for_fix
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 5.16.12-1 | 5.16.12-1 |
| Red Hat:enterprise_linux:8::baseos | bpftool | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-abi-stablelists | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-core | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-core | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-devel | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-modules | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-modules-extra | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-aarch64 | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-ppc64le | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-s390x | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-doc | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-modules | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-modules-extra | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-tools | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-tools-libs | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-zfcpdump | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-zfcpdump-core | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-zfcpdump-debuginfo | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-zfcpdump-devel | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-zfcpdump-modules | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
| Red Hat:enterprise_linux:8::baseos | kernel-zfcpdump-modules-extra | before 0:4.18.0-372.26.1.el8_6 | 0:4.18.0-372.26.1.el8_6 |
+61
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 4c3644b6c96c5daa5149e5abddc07234eea47c7c | Vendor (CNA) |
| Linux Linux | 62040f5cd7d937de547836e747b6aa8212fec573 | Vendor (CNA) |
| Linux Linux | 6f3c1fc53d86d580d8d6d749c4af23705e4f6f79 | Vendor (CNA) |
| Linux Linux | 72fdfc75d4217b32363cc80def3de2cb3fef3f02 | Vendor (CNA) |
| debian:linux | 5.16.12-1 · Debian:12 | Package registry (OSV) |
| red hat:bpftool-debuginfo | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debug-debuginfo | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debug-devel | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debug-devel-matched | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo-common-aarch64 | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo-common-ppc64le | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo-common-s390x | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo-common-x86_64 | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-devel | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-devel-matched | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| red hat:kernel-doc | 0:5.14.0-70.22.1.el9_0 · Red Hat:enterprise_linux:9::appstream | Package registry (OSV) |
| suse:kernel-azure | 4.12.14-16.200.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-default | 4.12.14-122.231.1 · SUSE:Linux Enterprise High Availability Extension 12 SP5 | Package registry (OSV) |
| suse:kernel-docs | 4.12.14-122.231.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-obs-build | 4.12.14-122.231.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-rt | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-rt_debug | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-source | 4.12.14-122.231.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-azure | 4.12.14-16.200.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-rt | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-syms | 4.12.14-122.231.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-syms-rt | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kgraft-patch-SLE12-SP5_Update_61 | 1-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/4c3644b6c96c5daa5149e5abddc07234eea47c7c
- git.kernel.org/stable/c/62040f5cd7d937de547836e747b6aa8212fec573
- git.kernel.org/stable/c/6f3c1fc53d86d580d8d6d749c4af23705e4f6f79
- git.kernel.org/stable/c/72fdfc75d4217b32363cc80def3de2cb3fef3f02
Vendor advisories and official records. Exploit/PoC links are deliberately left out.