# CVE-2025-39873: can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB

CVE-2025-39873 is fixed in 24 products on 1 platform, first by DEBIAN-CVE-2025-39873, released September 23, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-39873
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 23, 2025
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-39873

## Description

In the Linux kernel, the following vulnerability has been resolved:  can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB  can_put_echo_skb() takes ownership of the SKB and it may be freed during or after the call.  However, xilinx_can xcan_write_frame() keeps using SKB after the call.  Fix that by only calling can_put_echo_skb() after the code is done touching the SKB.  The tx_lock is held for the entire xcan_write_frame() execution and also on the can_get_echo_skb() side so the order of operations does not matter.  An earlier fix commit 3d3c817c3a40 ("can: xilinx_can: Fix usage of skb memory") did not move the can_put_echo_skb() call far enough.  [mkl: add "commit" in front of sha1 in patch description] [mkl: fix indention]

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dtb-aarch64 opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-64kb opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-64kb sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-azure opensuse-leap 15.6 | 6.4.0-150600.8.52.1 | [SUSE-SU-2025:03634-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03634-1.md) | Oct 17, 2025 |
| Linux | kernel-azure sles 15.6 | 6.4.0-150600.8.52.1 | [SUSE-SU-2025:03634-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03634-1.md) | Oct 17, 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 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-default opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-default sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-default-base opensuse-leap 15.6 | 6.4.0-150600.23.73.1.150600.12.32.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.6.1.160000.2.4 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-default-base sles 15.6 | 6.4.0-150600.23.73.1.150600.12.32.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-docs opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-docs sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-kvmsmall opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-livepatch-SLE15-SP6-RT_Update_16 sles 15.6 | 1-150600.1.3.1 | [SUSE-SU-2025:3751-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-3751-1.md) | Oct 23, 2025 |
| Linux | kernel-livepatch-SLE15-SP6_Update_16 sles 15.6 | 1-150600.13.3.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-obs-build sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-rt opensuse-leap 15.6 | 6.4.0-150600.10.55.1 | [SUSE-SU-2025:3751-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-3751-1.md) | Oct 23, 2025 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-rt_debug opensuse-leap 15.6 | 6.4.0-150600.10.55.1 | [SUSE-SU-2025:3751-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-3751-1.md) | Oct 23, 2025 |
| Linux | kernel-source opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-source sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-source-azure opensuse-leap 15.6 | 6.4.0-150600.8.52.1 | [SUSE-SU-2025:03634-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03634-1.md) | Oct 17, 2025 |
| Linux | kernel-source-azure sles 15.6 | 6.4.0-150600.8.52.1 | [SUSE-SU-2025:03634-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03634-1.md) | Oct 17, 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 | 6.4.0-150600.10.55.1 | [SUSE-SU-2025:3751-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-3751-1.md) | Oct 23, 2025 |
| Linux | kernel-syms opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-syms sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | kernel-syms-azure opensuse-leap 15.6 | 6.4.0-150600.8.52.1 | [SUSE-SU-2025:03634-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03634-1.md) | Oct 17, 2025 |
| Linux | kernel-syms-azure sles 15.6 | 6.4.0-150600.8.52.1 | [SUSE-SU-2025:03634-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03634-1.md) | Oct 17, 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 | 6.4.0-150600.10.55.1 | [SUSE-SU-2025:3751-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-3751-1.md) | Oct 23, 2025 |
| Linux | kernel-zfcpdump opensuse-leap 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 2025 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.6.1 | [OPENSUSE-SU-2025:20081-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2025-20081-1.md) | Nov 25, 2025 |
| Linux | kernel-zfcpdump sles 15.6 | 6.4.0-150600.23.73.1 | [SUSE-SU-2025:03600-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-03600-1.md) | Oct 15, 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 | 6.12.0-160000.6.1 | [SUSE-SU-2025:21139-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-21139-1.md) | Nov 25, 2025 |
| Linux | linux Debian 12.15 (bookworm) | 6.1.153-1 | [DEBIAN-CVE-2025-39873](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39873.md) | Sep 23, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.48-1 | [DEBIAN-CVE-2025-39873](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39873.md) | Sep 23, 2025 |
| Linux | linux Debian 14 | 6.16.8-1 | [DEBIAN-CVE-2025-39873](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39873.md) | Sep 23, 2025 |

---

Data as of 2026-11-08T13:06:02Z 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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