CVE-2026-72411

Summary

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

net: dsa: mxl862xx: fix use-after-free of DSA ports in crc_err_work

Upon an MDIO CRC error mxl862xx_crc_err_work_fn() walks the DSA ports and closes the CPU port conduits:

dsa_switch_for_each_cpu_port(dp, priv->ds)
	dev_close(dp->conduit);

mxl862xx_remove() unregisters the switch before cancelling this work:

set_bit(MXL862XX_FLAG_WORK_STOPPED, &priv->flags);
cancel_delayed_work_sync(&priv->stats_work);
dsa_unregister_switch(ds);
mxl862xx_host_shutdown(priv);

dsa_unregister_switch() frees the dsa_port objects. If a CRC error schedules the work during teardown it can run after the ports have been freed and dereference freed memory.

Guard the port walk with MXL862XX_FLAG_WORK_STOPPED, which is already set before dsa_unregister_switch(). DSA tears the ports down under rtnl_lock(), so checking the flag under rtnl_lock() means the work either runs before teardown and sees valid ports, or runs afterwards, observes the flag and skips the walk. This mirrors the host_flood_work handler, which skips torn-down ports under rtnl_lock().

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/cf52622fbc274eb4ca9a2066b258da2ae3dc7406
• https://git.kernel.org/stable/c/bcb3b8314611ed9cb4ff4bff484ef9b154fd1b83

• ←Previous
• Next→