CVE-2026-99192

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

net: bcmgenet: unshare the skb before writing the control block

bcmgenet stores first cb, last cb and bytes sent in the skb control block and reads them back on completion to free the skb and credit BQL. ether setup() leaves IFF TX SKB SHARING set, so the stack can resubmit a shared skb that is still in the ring. The next transmit overwrites last cb, so the earlier slots complete without crediting their bytes and BQL stalls the queue until the watchdog resets it.

Unshare the skb before writing the control block.

Reproduce with pktgen in clone skb mode, which hands the driver the same skb while earlier copies are still in the ring:

modprobe pktgen pg=/proc/net/pktgen echo "add device eth0" > $pg/kpktgend 0 echo "dst mac AA:BB:CC:DD:EE:FF" > $pg/eth0 echo "dst 192.0.2.1" > $pg/eth0 echo "clone skb 8" > $pg/eth0 echo "count 0" > $pg/eth0 echo start > $pg/pgctrl & sleep 5 echo stop > $pg/pgctrl wait cat /sys/class/net/eth0/queues/tx-0/byte queue limits/inflight

inflight stays nonzero on the now idle queue. clone skb 0 leaves it at zero.