CVE-2026-99192 json
net: bcmgenet: unshare the skb before writing the control block
published 2026-10-28 11 d ago modified 2026-10-30 9 d ago also EUVD-2026-111944
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Linux Linux 3.17, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13, 7.3
- linux Debian 13 6.12.115-2
- linux Debian 14 7.2.13-1
debian advisories DEBIAN-CVE-2026-99192
- linux Ubuntu 26.10 7.3.0-10.10
- linux-aws Ubuntu 26.10 7.3.0-1004.4
- linux-gcp Ubuntu 26.10 7.3.0-1004.4
- linux-raspi Ubuntu 26.10 7.3.0-1004.4
- linux-riscv Ubuntu 26.10 7.3.0-10.10.1
- linux-oracle Ubuntu 26.10 7.3.0-1004.4
- linux-realtime Ubuntu 26.10 7.3.0-10.10.1
ubuntu advisories UBUNTU-CVE-2026-99192
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel Azure Linux 3.0 6.6.161.1-1
azure linux advisories AZL-111359
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/c13d43c92bc89f494592a60e624a7c0c42218d36 commit
- git.kernel.org/stable/c/e5aa07c62e4fda1206d314c9ea36d67cd6b95cad commit
- git.kernel.org/stable/c/2e5fb9dd3aca0da534793ad8123b81deff396efe commit
- git.kernel.org/stable/c/40c04abcbc34e3afe338f41dae851ecbd72852ac commit
- git.kernel.org/stable/c/7939ad3b4db9eadf45a64f0524f38337a9494672 commit
- git.kernel.org/stable/c/89771ce4f8f67dcffae561b2ccac95c0f6e3aa01 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-99192 updated cvss 4.7
kernel: kernel: Denial of Service via shared packet buffer handling in bcmgenet
-
Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9affected: no fix available “Fix deferred”
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8not affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/c13d43c92bc89f494592a60e624a7c0c42218d36
- git.kernel.org /stable/c/e5aa07c62e4fda1206d314c9ea36d67cd6b95cad
- git.kernel.org /stable/c/2e5fb9dd3aca0da534793ad8123b81deff396efe
- git.kernel.org /stable/c/40c04abcbc34e3afe338f41dae851ecbd72852ac
- git.kernel.org /stable/c/7939ad3b4db9eadf45a64f0524f38337a9494672
- git.kernel.org /stable/c/89771ce4f8f67dcffae561b2ccac95c0f6e3aa01
Sources
- CVE List CVE-2026-99192
- NVD CVE-2026-99192
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