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]
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 23 Sep 2025 16:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Tue, 23 Sep 2025 06:15:00 +0000

Type Values Removed Values Added
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]
Title can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-23T06:00:46.157Z

Reserved: 2025-04-16T07:20:57.144Z

Link: CVE-2025-39873

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-09-23T06:15:46.670

Modified: 2025-09-23T06:15:46.670

Link: CVE-2025-39873

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-09-23T16:03:19Z