Unscored severity · published Oct 28, 2026
CVE-2026-99192
net: bcmgenet: unshare the skb before writing the control block
New
–
CVSS
–
EPSS
No
On KEV
Description
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.
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
f48bed16a756f5bc0244acd581f61968f7d7c2a4 before 40c04abcbc34e3afe338f41dae851ecbd72852ac; f48bed16a756f5bc0244acd581f61968f7d7c2a4 before 7939ad3b4db9eadf45a64f0524f38337a9494672; f48bed16a756f5bc0244acd581f61968f7d7c2a4 before 89771ce4f8f67dcffae561b2ccac95c0f6e3aa01; fb4ca2b4bc6712a6ad635df5b9b41131846589f9; 3.16.50 before 3.17; 4.13 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-99192
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-99192
git.kernel.org
https://git.kernel.org/stable/c/40c04abcbc34e3afe338f41dae851ecbd72852ac
git.kernel.org
https://git.kernel.org/stable/c/7939ad3b4db9eadf45a64f0524f38337a9494672
git.kernel.org
https://git.kernel.org/stable/c/89771ce4f8f67dcffae561b2ccac95c0f6e3aa01
More from Linux
9.8
CVE-2025-39682
tls: fix handling of zero-length records on the rx_list
8.8
CVE-2026-53266
netfilter: bridge: make ebt_snat ARP rewrite writable
7.8
CVE-2026-53362
ipv6: account for fraggap on the paged allocation path
7.8
CVE-2026-46300
net: skbuff: preserve shared-frag marker during coalescing
7.8
CVE-2026-31431
crypto: algif_aead - Revert to operating out-of-place
