Description

In the Linux kernel, the following vulnerability has been resolved:

powerpc/64s/interrupt: Fix interrupt exit race with security mitigation switch

The RFI and STF security mitigation options can flip the
interrupt_exit_not_reentrant static branch condition concurrently with
the interrupt exit code which tests that branch.

Interrupt exit tests this condition to set MSR[EE|RI] for exit, then
again in the case a soft-masked interrupt is found pending, to recover
the MSR so the interrupt can be replayed before attempting to exit
again. If the condition changes between these two tests, the MSR and irq
soft-mask state will become corrupted, leading to warnings and possible
crashes. For example, if the branch is initially true then false,
MSR[EE] will be 0 but PACA_IRQ_HARD_DIS clear and EE may not get
enabled, leading to warnings in irq_64.c.

Classification

CVE ID: CVE-2023-52740

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 17.83% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/86f7e423933608d536015a0f2eb9e0338c1227e0
https://git.kernel.org/stable/c/6f097c24815e67909a1fcc2c605586d02babd673
https://git.kernel.org/stable/c/2ea31e2e62bbc4d11c411eeb36f1b02841dbcab1

Timeline