# CVE-2025-39987: can: hi311x: populate ndo_change_mtu() to prevent buffer overflow

CVE-2025-39987 is fixed in 24 products on 1 platform, first by DEBIAN-CVE-2025-39987, released October 15, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-39987
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 15, 2025
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-39987

## Description

In the Linux kernel, the following vulnerability has been resolved:  can: hi311x: populate ndo_change_mtu() to prevent buffer overflow  Sending an PF_PACKET allows to bypass the CAN framework logic and to directly reach the xmit() function of a CAN driver. The only check which is performed by the PF_PACKET framework is to make sure that skb->len fits the interface's MTU.  Unfortunately, because the sun4i_can driver does not populate its net_device_ops->ndo_change_mtu(), it is possible for an attacker to configure an invalid MTU by doing, for example:    $ ip link set can0 mtu 9999  After doing so, the attacker could open a PF_PACKET socket using the ETH_P_CANXL protocol:  	socket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL))  to inject a malicious CAN XL frames. For example:  	struct canxl_frame frame = { 		.flags = 0xff, 		.len = 2048, 	};  The CAN drivers' xmit() function are calling can_dev_dropped_skb() to check that the skb is valid, unfortunately under above conditions, the malicious packet is able to go through can_dev_dropped_skb() checks:    1. the skb->protocol is set to ETH_P_CANXL which is valid (the      function does not check the actual device capabilities).    2. the length is a valid CAN XL length.  And so, hi3110_hard_start_xmit() receives a CAN XL frame which it is not able to correctly handle and will thus misinterpret it as a CAN frame. The driver will consume frame->len as-is with no further checks.  This can result in a buffer overflow later on in hi3110_hw_tx() on this line:  	memcpy(buf + HI3110_FIFO_EXT_DATA_OFF, 	       frame->data, frame->len);  Here, frame->len corresponds to the flags field of the CAN XL frame. In our previous example, we set canxl_frame->flags to 0xff. Because the maximum expected length is 8, a buffer overflow of 247 bytes occurs!  Populate net_device_ops->ndo_change_mtu() to ensure that the interface's MTU can not be set to anything bigger than CAN_MTU. By fixing the root cause, this prevents the buffer overflow.

## 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-2025-39987](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39987.md) | Oct 15, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.12.57-1 | [DEBIAN-CVE-2025-39987](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39987.md) | Oct 15, 2025 |
| Linux | linux Debian 14 | 6.16.10-1 | [DEBIAN-CVE-2025-39987](https://patchblox.com/security/data/fix/linux/debian-cve-2025-39987.md) | Oct 15, 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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