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TI-2026-64482 Aliases CVE-2026-98084GHSA-hcwg-2fch-4v4c

bpf: backtracking shouldn't clear outer frame R1-R5 for callbacks

Priority LOW 22Published · Updated

Key facts

Attack vector
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Privileges required
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User interaction
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Attack complexity
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Impact type
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Confidentiality · integrity · availability
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Fix status
Fixed

No CVSS vector from any source. Fix status from CNA.

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: backtracking shouldn't clear outer frame R1-R5 for callbacks When processing calls to bpf_loop() verifier marks R1 (and R4) as precise. R1 tracks loop iterations number and because of the 'callback_depth < R1' mechanics in check_helper_call() must be marked precise. However, precision propagation for R1 was broken, when bpf_loop() call was verified on a second iteration. Consider the following verification trace: - main: bpf_loop(nr_loops, callback ...) - callback: BPF_EXIT - main: bpf_loop(nr_loops, callback ...) - ... While the first visit of the call to bpf_loop() propagated R1 precision as expected, the second call to mark_chain_precision() in the check_helper_call() set R1, but it was immediately reset when backtrack_insn() processed preceding BPF_EXIT in the loop deleted in this patch. Because of that, the second visit of the call to bpf_loop() injected checkpoint with R1 not marked as precise. Which could trick the verifier into accepting unsafe programs. See the next patch for an example of such program. Commit is structured in a way to minimize conflicts when 'bpf' would be eventually merged with 'bpf-next'.

Why it matters now

EPSS 0.00168 6th percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.6.160, 6.12.114, 6.18.57 +2

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.6.15 to before 6.6.1606.6.160Patch availableCNA
LinuxLinux6.7 and later6.6.160, 6.12.114, 6.18.57, 7.2.7, 7.3Patch availableCNA
  • Linux VendorLinux Affected 6.6.15 to before 6.6.160 Fixed in 6.6.160 Patch available CNA
  • Linux VendorLinux Affected 6.7 and later Fixed in 6.6.160, 6.12.114, 6.18.57, 7.2.7, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.6.160
  • Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.114, 6.18.57, 7.2.7, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Not affected: 7 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat OpenShift Container Platform 4
  • Red Hat OpenShift Container Platform 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-98084
  2. 2026-10-03 Alias added: GHSA-hcwg-2fch-4v4c
  3. 2026-10-16 Fix available: Linux/Linux@3a39bc9707fbd1bef4df7318a9d02222741dda5b, Linux/[email protected] · CNA
  4. 2026-10-16 1 new reference · CNA
  5. 2026-10-19 Fix available: Linux/[email protected] · CNA
  6. 2026-10-21 Fix available: Linux/Linux@1ac58dab0a83d2c64e3b807a3a0b399f17a74110, Linux/[email protected], Linux/[email protected] +1 · CNA
  7. 2026-10-21 2 new references · CNA
  8. 2026-11-06 Affected versions changed · Red Hat
  9. 2026-11-06 CVSS score added · Red Hat

References

Other 5

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21727 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences