VulnerabilityPublished 28 Oct 2026

CVE-2026-99192: Linux kernel · net: bcmgenet: unshare the skb before writing the control block

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 89771ce4f8f67dcffae561b2ccac95c0f6e3aa01 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:58 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

Patch: Available – fixed in 89771ce4f8f67dcffae561b2ccac95c0f6e3aa01, 7939ad3b4db9eadf45a64f0524f38337a9494672, 40c04abcbc34e3afe338f41dae851ecbd72852ac +1

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to 89771ce4f8f67dcffae561b2ccac95c0f6e3aa01, 7939ad3b4db9eadf45a64f0524f38337a9494672, 40c04abcbc34e3afe338f41dae851ecbd72852ac or 3.17.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=3.16.50 <3.17	Fixed in 89771ce4f8f67dcffae561b2ccac95c0f6e3aa01 7939ad3b4db9eadf45a64f0524f38337a9494672 40c04abcbc34e3afe338f41dae851ecbd72852ac 3.17
LinuxLinux	Affected =4.13	Fixed in–

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.

References

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