CVE-2022-48943: KVM: x86/mmu: make apf token non-zero to fix bug
First published: Thu Aug 22 2024(Updated: )
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
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | <5.10.103 | |
| Linux Linux kernel | >=5.11<5.15.26 | |
| Linux Linux kernel | >=5.16<5.16.12 | |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.112-1 6.11.9-1 6.11.10-1 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://git.kernel.org/stable/c/4c3644b6c96c5daa5149e5abddc07234eea47c7c
- https://git.kernel.org/stable/c/62040f5cd7d937de547836e747b6aa8212fec573
- https://git.kernel.org/stable/c/6f3c1fc53d86d580d8d6d749c4af23705e4f6f79
- https://git.kernel.org/stable/c/72fdfc75d4217b32363cc80def3de2cb3fef3f02
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-48943
- https://nvd.nist.gov/vuln/detail/CVE-2022-48943
- https://launchpad.net/bugs/cve/CVE-2022-48943
- https://security-tracker.debian.org/tracker/CVE-2022-48943
- https://ubuntu.com/security/CVE-2022-48943
- https://git.kernel.org/linus/6f3c1fc53d86d580d8d6d749c4af23705e4f6f79
- agent/title
- agent/type
- agent/first-publish-date
- agent/author
- collector/nvd-api
- source/NVD
- agent/software-canonical-lookup
- agent/severity
- agent/remedy
- agent/softwarecombine
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- collector/usn-cve
- source/Ubuntu
- agent/references
- agent/tags
- agent/description
- agent/event
- collector/security-tracker-debian
- source/Debian
- vendor/linux
- canonical/linux linux kernel
- version/linux linux kernel/5.11
- version/linux linux kernel/5.16
- package-manager/debian