# CVE-2026-74719: net/smc: fix qentry overwrite for CONFIRM_LINK and ADD_LINK_CONT in smc_llc_event_handler()

CVE-2026-74719 is fixed in 18 products on 1 platform, first by DEBIAN-CVE-2026-74719, released August 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-74719
- Priority: Routine
- CVSS: 3.7 (Low)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 22, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74719

## Description

In the Linux kernel, the following vulnerability has been resolved:  net/smc: fix qentry overwrite for CONFIRM_LINK and ADD_LINK_CONT in smc_llc_event_handler()  The SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT branch in smc_llc_event_handler() stores an incoming qentry into the local LLC flow without first checking whether a qentry is already pending. If a malicious or buggy peer sends a second CONFIRM_LINK or ADD_LINK_CONT request while a flow is active and flow->qentry is already set, smc_llc_flow_qentry_set() overwrites the pointer without freeing the previous allocation, leaking one kmalloc-96 object per spurious message.  The sibling SMC_LLC_DELETE_LINK branch already has the correct !flow->qentry guard. Apply the same guard to the CONFIRM_LINK/ADD_LINK_CONT branch so that a duplicate message when qentry is already occupied falls through to break and is freed by the kfree(qentry) at the out: label, rather than silently leaking the existing allocation.  The response direction (smc_llc_rx_response()) is unaffected: it already guards with flow->qentry at the equivalent site and drops duplicate responses correctly.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-azure sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-default sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.38.1.160000.2.22 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-default-base sles 15.6 | 6.4.0-150600.23.138.1.150600.12.64.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.84.1.150700.17.47.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.38.1.160000.2.23 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-docs sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-livepatch-SLE15-SP6_Update_32 sles 15.6 | 1-150600.13.3.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_21 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:4640-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4640-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_22 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-obs-build sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-source sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-syms sles 15.6 | 6.4.0-150600.23.138.1 | [SUSE-SU-2026:4660-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4660-1.md) | Nov 7, 2026 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 |
| Linux | linux Debian 12.15 (bookworm) | 6.1.187-1 | [DEBIAN-CVE-2026-74719](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74719.md) | Aug 27, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.105-1 | [DEBIAN-CVE-2026-74719](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74719.md) | Aug 27, 2026 |
| Linux | linux Debian 14 | 7.1.9-1 | [DEBIAN-CVE-2026-74719](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74719.md) | Aug 27, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.107-1~deb12u1 | [DEBIAN-CVE-2026-74719](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74719.md) | Aug 27, 2026 |

---

Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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