CVE-2026-98574 net: bcmgenet: stop Tx NAPI before disabling the queues
A use-after-free in the Broadcom GENET network driver allows attackers to cause a denial of service or potentially execute code via race conditions during network interface suspension.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98574?
CVE-2026-98574 is an use after free vulnerability in Linux, published on 18 Oct 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: bcmgenet: stop Tx NAPI before disabling the queues
bcmgenet_netif_stop() and the Wake-on-LAN branch of bcmgenet_suspend() both disable the Tx queues first and stop Tx NAPI several steps later. A completion in flight calls netif_tx_wake_queue() in between, and nothing stops the queue again, so a transmit can reach the rings after they have been freed.
Close is safe because dev_deactivate_many() stops the qdisc first. bcmgenet_suspend() does not, so stop Tx NAPI before the queues on both paths.
KASAN on a Raspberry Pi CM4, driven from an MTU change because suspend freezes user space before the callback runs:
BUG: KASAN: use-after-free in bcmgenet_xmit+0x17f8/0x2258 Write of size 8 at addr ffffff8055844a68 by task ksoftirqd/0/14 bcmgenet_xmit+0x17f8/0x2258 dev_hard_start_xmit+0x13c/0x588 sch_direct_xmit+0x108/0x340 __dev_queue_xmit+0x1190/0x3848
Which versions are affected by CVE-2026-98574?
How do I fix CVE-2026-98574?
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-2026-98574 being exploited?
There is no known exploitation of CVE-2026-98574 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98574, DEBIAN-CVE-2026-98574, GHSA-rfvr-hxpg-f67j, UBUNTU-CVE-2026-98574.