CVE-2026-46330

In the Linux kernel, the following vulnerability has been resolved:

Revert net/smc: Introduce TCP ULP support

This reverts commit d7cd421da9da2cc7b4d25b8537f66db5c8331c40.

As reported by Al Viro, the TCP ULP support for SMC is fundamentally broken. The implementation attempts to convert an active TCP socket into an SMC socket by modifying the underlying struct file, dentry, and inode in-place, which violates core VFS invariants that assume these structures are immutable for an open file, creating a risk of use after free errors and general system instability.

Given the severity of this design flaw and the fact that cleaner alternatives (e.g., LD_PRELOAD, BPF) exist for legacy application transparency, the correct course of action is to remove this feature entirely.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/6c505d95c69e27dbf28fea29dc84d2498d69515c
• https://git.kernel.org/stable/c/df31a6b0a3057e66994ad6ccf5d95b9b9514f033