CVE-2026-46330: Revert "net/smc: Introduce TCP ULP support"
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., LDPRELOAD, BPF) exist for legacy application transparency, the correct course of action is to remove this feature entirely.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Remove
Remove
Linux kernel net/smc TCP ULP support (commit reverted)from your environment.Revert and remove the TCP ULP SMC feature that was introduced in Linux by reverting commit d7cd421da9da2cc7b4d25b8537f66db5c8331c40 ("net/smc: Introduce TCP ULP support"), as the vulnerability was resolved by this revert.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-46330?
CVE-2026-46330 has a risk rating of 54, indicating a medium severity level.
How does CVE-2026-46330 affect the Linux kernel?
CVE-2026-46330 affects the Linux kernel by reverting a commit related to TCP ULP support for SMC that was fundamentally broken.
What is the potential impact of CVE-2026-46330?
The potential impact of CVE-2026-46330 involves vulnerabilities related to use-after-free scenarios within the TCP ULP implementation.
How do I mitigate CVE-2026-46330?
To mitigate CVE-2026-46330, users should ensure they are running an updated version of the Linux kernel that has the vulnerability resolved.
When was CVE-2026-46330 published?
CVE-2026-46330 was published on June 9, 2026.