Incomplete Cleanup Affecting kernel-debug-uki-virt package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-RHEL9-KERNELDEBUGUKIVIRT-8256210
  • published23 Oct 2024
  • disclosed21 Oct 2024

Introduced: 21 Oct 2024

CVE-2024-47728  (opens in a new tab)
CWE-459  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:9 kernel-debug-uki-virt.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debug-uki-virt package and not the kernel-debug-uki-virt package as distributed by RHEL. See How to fix? for RHEL:9 relevant fixed versions and status.

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

bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error

For all non-tracing helpers which formerly had ARG_PTR_TO_{LONG,INT} as input arguments, zero the value for the case of an error as otherwise it could leak memory. For tracing, it is not needed given CAP_PERFMON can already read all kernel memory anyway hence bpf_get_func_arg() and bpf_get_func_ret() is skipped in here.

Also, the MTU helpers mtu_len pointer value is being written but also read. Technically, the MEM_UNINIT should not be there in order to always force init. Removing MEM_UNINIT needs more verifier rework though: MEM_UNINIT right now implies two things actually: i) write into memory, ii) memory does not have to be initialized. If we lift MEM_UNINIT, it then becomes: i) read into memory, ii) memory must be initialized. This means that for bpf_*_check_mtu() we're readding the issue we're trying to fix, that is, it would then be able to write back into things like .rodata BPF maps. Follow-up work will rework the MEM_UNINIT semantics such that the intent can be better expressed. For now just clear the *mtu_len on error path which can be lifted later again.

CVSS Scores

version 3.1