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.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
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| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
No solution or workaround provided in the CVE record.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Wed, 28 Oct 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-362 |
Wed, 28 Oct 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | net: bcmgenet: unshare the skb before writing the control block | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-28T10:35:48.686Z
Reserved: 2026-09-25T10:25:14.400Z
Link: CVE-2026-99192
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-28T11:17:40.207
Modified: 2026-10-28T11:17:40.207
Link: CVE-2026-99192
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-10-28T12:30:17Z