CVE-2024-47728

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

Published Oct 21, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4008-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-7276-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7277-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7301-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7303-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7303-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7303-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7304-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7310-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7311-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7384-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7384-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7385-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7386-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7403-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7468-1 Linux kernel (Azure, N-Series) vulnerabilities
History
Type Values Removed Values Added
Metrics threat_severity

Moderate

threat_severity

Low

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-459
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:39 PM
Reserved
Sep 30, 2024, 4:00 PM
Status
Modified
Published
Oct 21, 2024, 1:15 PM
Modified
Jun 17, 2026, 7:57 AM
Severity
Low
Public date
Oct 21, 2024, 12:00 AM