Red Hat: CVE-2024-45020: kernel: bpf: Fix a kernel verifier crash in stacksafe() (Multiple Advisories)

Red Hat: CVE-2024-45020: kernel: bpf: Fix a kernel verifier crash in stacksafe() (Multiple Advisories)

Severity

6

CVSS

(AV:L/AC:L/Au:M/C:C/I:N/A:C)

Published

09/11/2024

Created

02/11/2025

Added

02/10/2025

Modified

02/10/2025

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a kernel verifier crash in stacksafe() Daniel Hodges reported a kernel verifier crash when playing with sched-ext. Further investigation shows that the crash is due to invalid memory access in stacksafe(). More specifically, it is the following code: if (exact != NOT_EXACT && old->stack[spi].slot_type[i % BPF_REG_SIZE] != cur->stack[spi].slot_type[i % BPF_REG_SIZE]) return false; The 'i' iterates old->allocated_stack. If cur->allocated_stack < old->allocated_stack the out-of-bound access will happen. To fix the issue add 'i >= cur->allocated_stack' check such that if the condition is true, stacksafe() should fail. Otherwise, cur->stack[spi].slot_type[i % BPF_REG_SIZE] memory access is legal.

Solution(s)

• redhat-upgrade-kernel
• redhat-upgrade-kernel-rt

References

• CVE-2024-45020
• RHSA-2024:11486