CVE-2024-53089

/// Technical description

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

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References