Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix bpf_sock context code generation
Currently, the ctx access code reads the rx_queue_mapping
field with either a 4-byte or 2-byte load. The rest of the bits
in the register are marked known zero by the verifier. However,
the emitted ctx access code places in the register on certain
the special value (-1) using BPF_MOV_IMM64, which gets sign-extended
to turn on all the bits in the register. By shifting this value right,
the program ends up with a value at runtime above what the verifier
assumes is possible.
Fix this by ensuring the read value is as wide as the assumed size.
Use MOV32 instructions instead of MOV64 instructions to keep
the upper bits zero as assumed by the verifier. Also properly report
the size of the destination variable (the bpf_sock field, 4 bytes) instead
of the source (the socket field, 2 bytes).
bpf: Fix bpf_sock context code generation
Currently, the ctx access code reads the rx_queue_mapping
field with either a 4-byte or 2-byte load. The rest of the bits
in the register are marked known zero by the verifier. However,
the emitted ctx access code places in the register on certain
the special value (-1) using BPF_MOV_IMM64, which gets sign-extended
to turn on all the bits in the register. By shifting this value right,
the program ends up with a value at runtime above what the verifier
assumes is possible.
Fix this by ensuring the read value is as wide as the assumed size.
Use MOV32 instructions instead of MOV64 instructions to keep
the upper bits zero as assumed by the verifier. Also properly report
the size of the destination variable (the bpf_sock field, 4 bytes) instead
of the source (the socket field, 2 bytes).
Published:
2026-10-18
Score:
n/a
EPSS:
n/a
KEV:
No
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No solution or workaround provided in the CVE record.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
References
History
Sun, 18 Oct 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpf_sock context code generation Currently, the ctx access code reads the rx_queue_mapping field with either a 4-byte or 2-byte load. The rest of the bits in the register are marked known zero by the verifier. However, the emitted ctx access code places in the register on certain the special value (-1) using BPF_MOV_IMM64, which gets sign-extended to turn on all the bits in the register. By shifting this value right, the program ends up with a value at runtime above what the verifier assumes is possible. Fix this by ensuring the read value is as wide as the assumed size. Use MOV32 instructions instead of MOV64 instructions to keep the upper bits zero as assumed by the verifier. Also properly report the size of the destination variable (the bpf_sock field, 4 bytes) instead of the source (the socket field, 2 bytes). | |
| Title | bpf: Fix bpf_sock context code generation | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:19:02.747Z
Reserved: 2026-09-25T10:25:14.358Z
Link: CVE-2026-98590
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:11.610
Modified: 2026-10-18T16:17:11.610
Link: CVE-2026-98590
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.