CVE-2024-53089: LoongArch: KVM: Mark hrtimer to expire in hard interrupt context
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Mark hrtimer to expire in hard interrupt context
Like commit 2c0d278f3293f ("KVM: LAPIC: Mark hrtimer to expire in hard
interrupt context") and commit 9090825fa9974 ("KVM: arm/arm64: Let the
timer expire in hardirq context on RT"), On PREEMPT_RT enabled kernels
unmarked hrtimers are moved into soft interrupt expiry mode by default.
Then the timers are canceled from an preempt-notifier which is invoked
with disabled preemption which is not allowed on PREEMPT_RT.
The timer callback is short so in could be invoked in hard-IRQ context.
So let the timer expire on hard-IRQ context even on -RT.
This fix a "scheduling while atomic" bug for PREEMPT_RT enabled kernels:
BUG: scheduling while atomic: qemu-system-loo/1011/0x00000002
Modules linked in: amdgpu rfkill nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat ns
CPU: 1 UID: 0 PID: 1011 Comm: qemu-system-loo Tainted: G W 6.12.0-rc2+ #1774
Tainted: [W]=WARN
Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.0-prebeta9 10/21/2022
Stack : ffffffffffffffff 0000000000000000 9000000004e3ea38 9000000116744000
90000001167475a0 0000000000000000 90000001167475a8 9000000005644830
90000000058dc000 90000000058dbff8 9000000116747420 0000000000000001
0000000000000001 6a613fc938313980 000000000790c000 90000001001c1140
00000000000003fe 0000000000000001 000000000000000d 0000000000000003
0000000000000030 00000000000003f3 000000000790c000 9000000116747830
90000000057ef000 0000000000000000 9000000005644830 0000000000000004
0000000000000000 90000000057f4b58 0000000000000001 9000000116747868
900000000451b600 9000000005644830 9000000003a13998 0000000010000020
00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d
...
Call Trace:
[<9000000003a13998>] show_stack+0x38/0x180
[<9000000004e3ea34>] dump_stack_lvl+0x84/0xc0
[<9000000003a71708>] __schedule_bug+0x48/0x60
[<9000000004e45734>] __schedule+0x1114/0x1660
[<9000000004e46040>] schedule_rtlock+0x20/0x60
[<9000000004e4e330>] rtlock_slowlock_locked+0x3f0/0x10a0
[<9000000004e4f038>] rt_spin_lock+0x58/0x80
[<9000000003b02d68>] hrtimer_cancel_wait_running+0x68/0xc0
[<9000000003b02e30>] hrtimer_cancel+0x70/0x80
[<ffff80000235eb70>] kvm_restore_timer+0x50/0x1a0 [kvm]
[<ffff8000023616c8>] kvm_arch_vcpu_load+0x68/0x2a0 [kvm]
[<ffff80000234c2d4>] kvm_sched_in+0x34/0x60 [kvm]
[<9000000003a749a0>] finish_task_switch.isra.0+0x140/0x2e0
[<9000000004e44a70>] __schedule+0x450/0x1660
[<9000000004e45cb0>] schedule+0x30/0x180
[<ffff800002354c70>] kvm_vcpu_block+0x70/0x120 [kvm]
[<ffff800002354d80>] kvm_vcpu_halt+0x60/0x3e0 [kvm]
[<ffff80000235b194>] kvm_handle_gspr+0x3f4/0x4e0 [kvm]
[<ffff80000235f548>] kvm_handle_exit+0x1c8/0x260 [kvm]
Security readout for executives and security teams
Plain-English summary
This is a Linux kernel availability issue affecting LoongArch systems running KVM with PREEMPT_RT enabled. A local user could trigger a kernel scheduling failure path that can disrupt service availability. It does not indicate data theft or privilege escalation in the provided sources.
Executive priority
Handle through normal patch governance, with priority for LoongArch virtualization infrastructure. The business risk is service disruption on a specialized platform, not broad enterprise exposure or confirmed active exploitation.
Technical view
The LoongArch KVM timer used an hrtimer mode that can move to softirq expiry on PREEMPT_RT kernels. KVM can cancel that timer from a preempt-notifier while preemption is disabled, producing a “scheduling while atomic” bug. The fix marks the timer to expire in hard interrupt context.
Likely exposure
Exposure appears narrow: LoongArch Linux hosts using KVM virtualization on PREEMPT_RT-enabled kernels. General Linux systems, non-LoongArch architectures, or hosts not using KVM/RT kernels are less likely to be affected based on the source description.
Exploitation context
CVSS indicates local access, low complexity, low privileges, no user interaction, and high availability impact. The bundle does not show KEV listing or cited evidence of active exploitation. Treat this as a local denial-of-service risk, not a remotely exploitable compromise.
Researcher notes
The public record describes a kernel correctness fix rather than a detailed exploit scenario. Validate exposure by architecture, KVM use, RT kernel configuration, and fixed kernel lineage. Evidence is incomplete for distribution-specific affected and fixed versions.
Mitigation direction
Update affected Linux kernels to a vendor release containing the referenced stable fixes.
Prioritize LoongArch virtualization hosts running KVM and PREEMPT_RT.
Follow Linux distribution or hardware vendor advisories for exact fixed package versions.
Restrict untrusted local access to affected virtualization hosts until patched.
Validation and detection
Inventory LoongArch hosts and confirm whether KVM virtualization is enabled.
Check whether the running kernel is PREEMPT_RT-enabled.
Verify the kernel contains fixes matching the referenced stable commits.
Review kernel logs for “scheduling while atomic” involving qemu-system-loo or KVM.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Potential ATT&CK relevance
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
cve · low confidence lookup
CVE-2024-53089 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.