CVEvulnerability
CVE-2026-43070
7.8 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-05-05
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-125
Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reset register ID for BPF_END value tracking
When a register undergoes a BPF_END (byte swap) operation, its scalar
value is mutated in-place. If this register previously shared a scalar ID
with another register (e.g., after an `r1 = r0` assignment), this tie must
be broken.
Currently, the verifier misses resetting `dst_reg->id` to 0 for BPF_END.
Consequently, if a conditional jump checks the swapped register, the
verifier incorrectly propagates the learned bounds to the linked register,
leading to false confidence in the linked register's value and potentially
allowing out-of-bounds memory accesses.
Fix this by explicitly resetting `dst_reg->id` to 0 in the BPF_END case
to break the scalar tie, similar to how BPF_NEG handles it via
`__mark_reg_known`.
Affected configurations
• linux linux kernel (>= 6.18.17 < 6.18.21)
• linux linux kernel (>= 6.19.7 < 6.19.11)
• linux linux kernel 7.0
Related
Weakness · CWE (1)
- CWE-125 Out-of-bounds Read weakness