# CVE-2026-74713: vhost_iotlb: bound map allocation in add_range

CVE-2026-74713 is fixed in 16 products on 1 platform, first by DEBIAN-CVE-2026-74713, released September 4, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-74713
- Priority: High
- CVSS: 7.1 (Moderate)
- EPSS: 0.0014
- 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-2026-74713

## Description

In the Linux kernel, the following vulnerability has been resolved:  vhost_iotlb: bound map allocation in add_range  vhost_iotlb_add_range_ctx() only retires an old entry when the table has a non-zero limit, has exactly reached that limit and has VHOST_IOTLB_FLAG_RETIRE set. Non-retiring tables can keep allocating entries after reaching their configured limit.  Existing vhost devices allocate their IOTLB with max_iotlb_entries from vhost.c, which defaults to 2048 and is tunable by module parameter. Use the caller-provided limit at the allocation point instead of adding a separate default in the common IOTLB helper, and reject non-positive values in vhost paths that can report an error.  Other vhost IOTLB users should not create zero-limit tables when entries can be populated from userspace or guest-controlled requests. Add caller-side max_iotlb_entries parameters for mlx5 vDPA, VDUSE and vhost-vDPA. Reject non-positive VDUSE and vhost-vDPA values, and require at least two entries for vdpa_sim and mlx5 vDPA paths that install full-range mappings, since those mappings are split into two IOTLB entries.  Handle full-range mappings in the common helper by checking that the IOTLB can hold both split entries before inserting the first half. This avoids returning an error after leaving a half mapping behind.  When the table is full, keep the existing retire behavior for retiring tables and return -ENOSPC for non-retiring tables. Reuse the retired map node instead of freeing it and allocating a replacement, so a stream of IOTLB updates cannot keep forcing GFP_ATOMIC allocations after the table has reached its limit. If a zero-limit IOTLB still reaches the common helper, treat it as a configuration error and return -EINVAL.  I found this bug myself, though the patch was written with AI assistance.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24197-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24197-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.39.1.160000.2.25 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.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 | 6.12.0-160000.39.1.160000.2.26 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.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 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.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 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 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 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-74713](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74713.md) | Sep 4, 2026 |
| Linux | linux Debian 14 | 7.1.9-1 | [DEBIAN-CVE-2026-74713](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74713.md) | Sep 4, 2026 |

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Data as of 2026-11-10T01:44:33Z 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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