CVE-2026-72411 net: dsa: mxl862xx: fix use-after-free of DSA ports in crc_err_work
A use-after-free vulnerability in the Linux kernel's mxl862xx DSA driver allows attackers to cause denial of service or execute code via race conditions during device removal.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72411?
CVE-2026-72411 is a high-severity use after free vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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().
Which versions are affected by CVE-2026-72411?
How do I fix CVE-2026-72411?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-72411 being exploited?
There is no known exploitation of CVE-2026-72411 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-72411, GHSA-426f-jh2p-2383, UBUNTU-CVE-2026-72411.