CVE-2025-21637: sctp: sysctl: udp_port: avoid using current->nsproxy
First published: Sun Jan 19 2025(Updated: )
In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: udp_port: 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, but that would increase the size of this fix, while 'sctp.ctl_sock' still needs to be retrieved from 'net' structure.
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Kernel | ||
| Linux Kernel | >=5.11<5.15.177 | |
| Linux Kernel | >=5.16<6.1.125 | |
| Linux Kernel | >=6.2<6.6.72 | |
| Linux Kernel | >=6.7<6.12.10 | |
| Linux Kernel | =6.13-rc1 | |
| Linux Kernel | =6.13-rc2 | |
| Linux Kernel | =6.13-rc3 | |
| Linux Kernel | =6.13-rc4 | |
| Linux Kernel | =6.13-rc5 | |
| Linux Kernel | =6.13-rc6 |
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Reference Links
- https://git.kernel.org/stable/c/e919197fb8616331f5dc81e4c3cc3d12769cb725
- https://git.kernel.org/stable/c/55627918febdf9d71107a1e68d1528dc591c9a15
- https://git.kernel.org/stable/c/5b77d73f3be5102720fb685b9e6900e3500e1096
- https://git.kernel.org/stable/c/c10377bbc1972d858eaf0ab366a311b39f8ef1b6
- https://git.kernel.org/stable/c/0a0966312ac3eedd7f5f2a766ed4702df39a9a65
Frequently Asked Questions
What is the severity of CVE-2025-21637?
CVE-2025-21637 is classified as a moderate severity vulnerability.
How do I fix CVE-2025-21637?
To fix CVE-2025-21637, upgrade to the patched version of the Linux kernel as specified in the latest updates.
What are the potential consequences of CVE-2025-21637?
Exploitation of CVE-2025-21637 may lead to unexpected behavior in the Linux kernel, potentially affecting system stability.
Which versions of the Linux kernel are affected by CVE-2025-21637?
CVE-2025-21637 affects various versions of the Linux kernel prior to the fix being applied.
Is CVE-2025-21637 specific to certain Linux distributions?
CVE-2025-21637 can potentially affect all distributions using the vulnerable versions of the Linux kernel.
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