CVE-2025-22048: Linux kernel · LoongArch: BPF: Don't override subprog's return value
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 30 Oct 2026, 13:34 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Linux Linux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: LoongArch: BPF: Don't override subprog's return value The verifier test `calls: div by 0 in subprog` triggers a panic at the ld.bu instruction. The ld.bu insn is trying to load byte from memory address returned by the subprog. The subprog actually set the correct address at the a5 register (dedicated register for BPF return values). But at commit 73c359d1d356 ("LoongArch: BPF: Sign-extend return values") we also sign extended a5 to the a0 register (return value in LoongArch). For function call insn, we later propagate the a0 register back to a5 register. This is right for native calls but wrong for bpf2bpf calls which expect zero-extended return value in a5 register. So only move a0 to a5 for native calls (i.e. non-BPF_PSEUDO_CALL).
References
- git.kernel.org/stable/c/d99845f672cce0b610f7c51248ef95d7df63927e (opens in a new tab)
- git.kernel.org/stable/c/7df2696256a034405d3c5a71b3a4c54725de4404 (opens in a new tab)
- git.kernel.org/stable/c/223d565d8892481684091cfbaf3466f2b0e289d3 (opens in a new tab)
- git.kernel.org/stable/c/780628a780b622759d9e5adc76d15432144da1a3 (opens in a new tab)
- git.kernel.org/stable/c/996e90ab446641553e8e21707b38b9709605e0e0 (opens in a new tab)
- git.kernel.org/stable/c/60f3caff1492e5b8616b9578c4bedb5c0a88ed14 (opens in a new tab)