CVE-2026-43232

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: wan: farsync: Fix use-after-free bugs caused by unfinished tasklets

When the FarSync T-series card is being detached, the fst_card_info is

deallocated in fst_remove_one(). However, the fst_tx_task or fst_int_task

may still be running or pending, leading to use-after-free bugs when the

already freed fst_card_info is accessed in fst_process_tx_work_q() or

fst_process_int_work_q().

A typical race condition is depicted below:

CPU 0 (cleanup) | CPU 1 (tasklet)

| fst_start_xmit()

fst_remove_one() | tasklet_schedule()

unregister_hdlc_device()|

| fst_process_tx_work_q() //handler

kfree(card) //free | do_bottom_half_tx()

| card-> //use

The following KASAN trace was captured:

==================================================================

BUG: KASAN: slab-use-after-free in do_bottom_half_tx+0xb88/0xd00

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References