CVE-2025-39873: Debian Linux

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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]

Affected products

• Debian Debian Linux: version 11.0 only
• Linux Linux Kernel: from 4.19, before 5.15.194 (fixed in 5.15.194); from 5.16, before 6.1.153 (fixed in 6.1.153); from 6.2, before 6.6.107 (fixed in 6.6.107); from 6.7, before 6.12.48 (fixed in 6.12.48); from 6.13, before 6.16.8 (fixed in 6.16.8); version 6.17 only

Published 2025-09-23. Last modified 2026-07-30.