CVE-2025-21870: Linux kernel · NULL Pointer Dereference
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 30 Oct 2026, 16:33 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 27 Mar 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.
Description
In the Linux kernel, the following vulnerability has been resolved: ASoC: SOF: ipc4-topology: Harden loops for looking up ALH copiers Other, non DAI copier widgets could have the same stream name (sname) as the ALH copier and in that case the copier->data is NULL, no alh_data is attached, which could lead to NULL pointer dereference. We could check for this NULL pointer in sof_ipc4_prepare_copier_module() and avoid the crash, but a similar loop in sof_ipc4_widget_setup_comp_dai() will miscalculate the ALH device count, causing broken audio. The correct fix is to harden the matching logic by making sure that the 1. widget is a DAI widget - so dai = w->private is valid 2. the dai (and thus the copier) is ALH copier
References
- nvd.nist.gov/vuln/detail/CVE-2025-21870 (opens in a new tab)
- git.kernel.org/stable/c/6b6b47c1aa717a0ed3400e00a81dfea686a41d7f (opens in a new tab)
- git.kernel.org/stable/c/6fd60136d256b3b948333ebdb3835f41a95ab7ef (opens in a new tab)
- git.kernel.org/stable/c/87c8768a96092ce75cd47fe076db5080db7ac515 (opens in a new tab)
- git.kernel.org/stable/c/93c6c2e5801aab09ef1ef99f248f3cd323c3f152 (opens in a new tab)
- git.kernel.org/stable/c/ec8f5a4fe296c311d4b45db7a25a0e9e69802372 (opens in a new tab)