CVE-2026-46330

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxd7cd421da9da2cc7b4d25b8537f66db5c8331c40 < 6c505d95c69e27dbf28fea29dc84d2498d69515caffected
LinuxLinuxd7cd421da9da2cc7b4d25b8537f66db5c8331c40 < df31a6b0a3057e66994ad6ccf5d95b9b9514f033affected
LinuxLinux5.17affected
LinuxLinux0 < 5.17unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References