Updated: 2025-11-10 00:35:41.667609
Description:
In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is used.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | MEDIUM | 5.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 23:36:06 | CVE-2025-21640 is a local-only null‑pointer dereference in the SCTP sysctl handler (cookie_hmac_al... | |
| CentOS 7 ELS | kernel | 3.10.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 23:36:05 | Ignored due to low severity | |
| CentOS 8.4 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 23:36:05 | Ignored due to low severity | |
| CentOS 8.5 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 23:36:06 | Ignored due to low severity | |
| CentOS Stream 8 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 23:36:05 | Ignored due to low severity | |
| CloudLinux 7 ELS | kernel | 3.10.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 21:45:14 | Ignored due to low severity | |
| Oracle Linux 7 ELS | kernel | 3.10.0 | 5.5 | MEDIUM | Ignored | 2025-03-02 23:36:05 | Ignored due to low severity | |
| Oracle Linux 7 ELS | kernel-uek | 5.4.17 | 5.5 | MEDIUM | Released | CLSA-2025:1746479711 | 2025-05-08 04:11:32 | Ignored due to low severity |
| RHEL 7 ELS | kernel | 3.10.0 | 5.5 | MEDIUM | Ignored | 2025-05-24 02:22:55 | Ignored due to low severity | |
| TuxCare 9.6 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Ignored | 2025-07-05 02:18:10 | This flaw is confined to the SCTP sysctl handler (net.sctp.cookie_hmac_alg) and is only reachable on... |