# CVE-2025-40043: net: nfc: nci: Add parameter validation for packet data

CVE-2025-40043 is fixed in 24 products on 1 platform, first by DEBIAN-CVE-2025-40043, released October 28, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-40043
- Priority: High
- CVSS: 8.8 (Moderate)
- EPSS: 0.0031
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 28, 2025
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40043

## Description

In the Linux kernel, the following vulnerability has been resolved:  net: nfc: nci: Add parameter validation for packet data  Syzbot reported an uninitialized value bug in nci_init_req, which was introduced by commit 5aca7966d2a7 ("Merge tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools").  This bug arises due to very limited and poor input validation that was done at nic_valid_size(). This validation only validates the skb->len (directly reflects size provided at the userspace interface) with the length provided in the buffer itself (interpreted as NCI_HEADER). This leads to the processing of memory content at the address assuming the correct layout per what opcode requires there. This leads to the accesses to buffer of `skb_buff->data` which is not assigned anything yet.  Following the same silent drop of packets of invalid sizes at `nic_valid_size()`, add validation of the data in the respective handlers and return error values in case of failure. Release the skb if error values are returned from handlers in `nci_nft_packet` and effectively do a silent drop  Possible TODO: because we silently drop the packets, the call to `nci_request` will be waiting for completion of request and will face timeouts. These timeouts can get excessively logged in the dmesg. A proper handling of them may require to export `nci_request_cancel` (or propagate error handling from the nft packets handlers).

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dtb-aarch64 opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-64kb opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-64kb sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-azure opensuse-leap 15.6 | 6.4.0-150600.8.55.1 | [SUSE-SU-2025:4128-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4128-1.md) | Nov 18, 2025 |
| Linux | kernel-azure sles 15.6 | 6.4.0-150600.8.55.1 | [SUSE-SU-2025:4128-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4128-1.md) | Nov 18, 2025 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.20.18.1 | [SUSE-SU-2025:4132-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4132-1.md) | Nov 18, 2025 |
| Linux | kernel-debug opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-default opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-default sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-default-base opensuse-leap 15.6 | 6.4.0-150600.23.78.1.150600.12.34.2 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.6.1.160000.2.4 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-default-base sles 15.6 | 6.4.0-150600.23.78.1.150600.12.34.2 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.22.1.150700.17.15.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.6.1.160000.2.4 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-docs opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-docs sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-kvmsmall opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-livepatch-SLE15-SP6-RT_Update_17 sles 15.6 | 1-150600.1.3.1 | [SUSE-SU-2025:4301-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4301-1.md) | Nov 28, 2025 |
| Linux | kernel-livepatch-SLE15-SP6_Update_17 sles 15.6 | 1-150600.13.5.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-livepatch-SLE15-SP7-RT_Update_6 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2025:4141-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4141-1.md) | Nov 19, 2025 |
| Linux | kernel-livepatch-SLE15-SP7_Update_6 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-obs-build opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-obs-build sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-obs-qa opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-rt opensuse-leap 15.6 | 6.4.0-150600.10.58.1 | [SUSE-SU-2025:4301-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4301-1.md) | Nov 28, 2025 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-rt_debug opensuse-leap 15.6 | 6.4.0-150600.10.58.1 | [SUSE-SU-2025:4301-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4301-1.md) | Nov 28, 2025 |
| Linux | kernel-source opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-source sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-source-azure opensuse-leap 15.6 | 6.4.0-150600.8.55.1 | [SUSE-SU-2025:4128-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4128-1.md) | Nov 18, 2025 |
| Linux | kernel-source-azure sles 15.6 | 6.4.0-150600.8.55.1 | [SUSE-SU-2025:4128-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4128-1.md) | Nov 18, 2025 |
| Linux | kernel-source-azure sles 15.7 | 6.4.0-150700.20.18.1 | [SUSE-SU-2025:4132-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4132-1.md) | Nov 18, 2025 |
| Linux | kernel-source-rt opensuse-leap 15.6 | 6.4.0-150600.10.58.1 | [SUSE-SU-2025:4301-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4301-1.md) | Nov 28, 2025 |
| Linux | kernel-syms opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-syms sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | kernel-syms-azure opensuse-leap 15.6 | 6.4.0-150600.8.55.1 | [SUSE-SU-2025:4128-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4128-1.md) | Nov 18, 2025 |
| Linux | kernel-syms-azure sles 15.6 | 6.4.0-150600.8.55.1 | [SUSE-SU-2025:4128-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4128-1.md) | Nov 18, 2025 |
| Linux | kernel-syms-azure sles 15.7 | 6.4.0-150700.20.18.1 | [SUSE-SU-2025:4132-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4132-1.md) | Nov 18, 2025 |
| Linux | kernel-syms-rt opensuse-leap 15.6 | 6.4.0-150600.10.58.1 | [SUSE-SU-2025:4301-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4301-1.md) | Nov 28, 2025 |
| Linux | kernel-zfcpdump opensuse-leap 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.7.1 | [OPENSUSE-SU-2025:20091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20091-1.md) | Nov 26, 2025 |
| Linux | kernel-zfcpdump sles 15.6 | 6.4.0-150600.23.78.1 | [SUSE-SU-2025:4140-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4140-1.md) | Nov 19, 2025 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.22.1 | [SUSE-SU-2025:4057-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4057-1.md) | Nov 11, 2025 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.7.1 | [SUSE-SU-2025:21147-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21147-1.md) | Nov 26, 2025 |
| Linux | linux Debian 12.15 (bookworm) | 6.1.158-1 | [DEBIAN-CVE-2025-40043](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40043.md) | Oct 28, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.57-1 | [DEBIAN-CVE-2025-40043](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40043.md) | Oct 28, 2025 |
| Linux | linux Debian 14 | 6.17.6-1 | [DEBIAN-CVE-2025-40043](https://patchblox.com/security/data/fix/linux/debian-cve-2025-40043.md) | Oct 28, 2025 |

---

Data as of 2026-11-09T01:18:40Z 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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