published October 18, 2026
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