Revert "net/smc: Introduce TCP ULP support"
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.57, 6.19.4, 7.0
Red Hat 1 advisory
- RHSA-2026:66180 Released 2026-09-10 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.46.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.46.1.el9_8, kernel-64k-devel-5.14.0-687.46.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.46.1.el9_8, kernel-64k-5.14.0-687.46.1.el9_8, kernel-64k-core-5.14.0-687.46.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.46.1.el9_8, libperf-5.14.0-687.46.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-64k-5.14.0-687.46.1.el9_8, kernel-rt-64k-core-5.14.0-687.46.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-core-5.14.0-687.46.1.el9_8, kernel-rt-debug-5.14.0-687.46.1.el9_8 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:66180 |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46330
- 2026-10-03 Alias added: GHSA-fm5x-69c3-7mfj
- 2026-10-16 Fix available: Linux/[email protected], Linux/Linux@dc24e03be0e4bb2aad1a9b272c4f86de3b11969a · CNA
- 2026-10-16 1 new reference · CNA
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
- 2026-10-21 Fix available: Linux/[email protected], Linux/[email protected], Linux/Linux@74d33525db50d9d95156c79cc874752654e66e70 +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@c7cb174a1edc80fe1f75b169a57726ed46704074 · CNA
- 2026-10-30 1 new reference · CNA
References
Patch 2
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-46330 · CVE Program
- CVE-2026-46330 · NVD
- FIRST EPSS
- GHSA-fm5x-69c3-7mfj · GitHub Advisory Database · CC BY 4.0
- CVE-2026-46330 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences