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

bpf: Reject non-scalar bpf_loop iteration counts

bpf_loop() declares its nr_loops argument as ARG_ANYTHING. Privileged
programs may pass pointer values to such arguments, so check_func_arg()
lets a pointer-valued R1 reach the helper-specific checks.

Since commit bb124da69c47 ("bpf: keep track of max number of bpf_loop
callback iterations"), the verifier marks R1 precise and reads its upper
bound to limit callback simulation. Precision backtracking only accepts
scalar registers, so passing a pointer instead triggers the "backtracking
misuse" verifier warning. Kernels with panic_on_warn enabled subsequently
panic.

Introduce ARG_SCALAR for helper arguments that only accept scalar values
and use it for bpf_loop() nr_loops. Generic helper argument validation then
rejects pointers before loop inlining and precision processing.

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Sat, 03 Oct 2026 11:15:00 +0000


Wed, 30 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20

Tue, 29 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-617
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

Low


Fri, 25 Sep 2026 17:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20

Fri, 25 Sep 2026 10:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: bpf: Reject non-scalar bpf_loop iteration counts bpf_loop() declares its nr_loops argument as ARG_ANYTHING. Privileged programs may pass pointer values to such arguments, so check_func_arg() lets a pointer-valued R1 reach the helper-specific checks. Since commit bb124da69c47 ("bpf: keep track of max number of bpf_loop callback iterations"), the verifier marks R1 precise and reads its upper bound to limit callback simulation. Precision backtracking only accepts scalar registers, so passing a pointer instead triggers the "backtracking misuse" verifier warning. Kernels with panic_on_warn enabled subsequently panic. Introduce ARG_SCALAR for helper arguments that only accept scalar values and use it for bpf_loop() nr_loops. Generic helper argument validation then rejects pointers before loop inlining and precision processing.
Title bpf: Reject non-scalar bpf_loop iteration counts
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T09:12:12.779Z

Reserved: 2026-09-25T10:19:56.068Z

Link: CVE-2026-98007

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T11:17:28.967

Modified: 2026-10-19T10:17:52.070

Link: CVE-2026-98007

cve-icon Redhat

Severity : Low

Publid Date: 2026-09-25T00:00:00Z

Links: CVE-2026-98007 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-30T14:30:18Z

Weaknesses