CVE-2026-72393: eth: fbnic: don't cache shinfo across skb realloc

Published Aug 15, 2026
·
Updated

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

eth: fbnic: don't cache shinfo across skb realloc

fbnictxlso() calls skbcowhead() which may reallocate the skb including the shared info. We can't use the pointer calculated before the call.

BUG: KASAN: slab-use-after-free in fbnictxlso.isra.0+0x668/0x8e0 Read of size 4 at addr ff110000262edd98 by task swapper/5/0 Call Trace: fbnictxlso.isra.0+0x668/0x8e0 fbnicxmitframe+0x622/0xba0 devhardstartxmit+0xf4/0x620

Allocated by task 8653: allocskb+0x11e/0x5f0 allocskbwithfrags+0xcc/0x6c0 sockallocsendpskb+0x327/0x3f0 ipappenddata+0x188b/0x47a0 ipmakeskb+0x24a/0x300 udpsendmsg+0x14d2/0x21e0

Freed by task 0: kfree+0x123/0x5a0 pskbexpandhead+0x36c/0xfa0 fbnictxlso.isra.0+0x500/0x8e0 fbnicxmitframe+0x622/0xba0 devhardstartxmit+0xf4/0x620 schdirectxmit+0x25b/0x1100

The buggy address belongs to the object at ff110000262edc40 which belongs to the cache skbuffsmallhead of size 640 The buggy address is located 344 bytes inside of freed 640-byte region [ff110000262edc40, ff110000262ede

Affected Software

130 affected componentsFixes available
Linux Linux kernel
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.8*
ubuntu/linux-intel-5.13*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.8*
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle-6.5*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0<7.0.0-1013.13~24.04.1
7.0.0-1013.13~24.04.1
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0<7.0.0-1017.17~24.04.1
7.0.0-1017.17~24.04.1
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0<7.0.0-1016.16~24.04.1
7.0.0-1016.16~24.04.1
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0<7.0.0-1013.13~24.04.1
7.0.0-1013.13~24.04.1
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-34.34~24.04.1
7.0.0-34.34~24.04.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0<7.0.0-1024.25~24.04.1
7.0.0-1024.25~24.04.1
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0<7.0.0-1012.12~24.04.1
7.0.0-1012.12~24.04.1
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-34.34.1~24.04.1
7.0.0-34.34.1~24.04.1
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux<7.0.0-34.34
7.0.0-34.34
ubuntu/linux-aws<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-azure<7.0.0-1017.17
7.0.0-1017.17
ubuntu/linux-azure-fde<7.0.0-1016.16
7.0.0-1016.16
ubuntu/linux-gcp<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-gke<7.0.0-1007.8
7.0.0-1007.8
ubuntu/linux-ibm<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-nvidia*
ubuntu/linux-nvidia-bos<7.0.0-2022.23
7.0.0-2022.23
ubuntu/linux-oem-7.0<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-oracle<7.0.0-1012.12
7.0.0-1012.12
ubuntu/linux-raspi<7.0.0-1020.20
7.0.0-1020.20
ubuntu/linux-realtime<7.0.0-34.34.1
7.0.0-34.34.1
ubuntu/linux-riscv<7.0.0-34.34.1
7.0.0-34.34.1
ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13~24.04.1
  2. Upgrade

    Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17~24.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-fde-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.16~24.04.1
  4. Upgrade

    Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13~24.04.1
  5. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-34.34~24.04.1
  6. Upgrade

    Upgrade ubuntu/linux-nvidia-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1024.25~24.04.1
  7. Upgrade

    Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1012.12~24.04.1
  8. Upgrade

    Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-34.34.1~24.04.1
  9. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 7.0.0-34.34
  10. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  11. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 7.0.0-1017.17
  12. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 7.0.0-1016.16
  13. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  14. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 7.0.0-1007.8
  15. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  16. Upgrade

    Upgrade ubuntu/linux-nvidia-bos to a version that resolves this vulnerability.

    Fixed in 7.0.0-2022.23
  17. Upgrade

    Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  18. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 7.0.0-1012.12
  19. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 7.0.0-1020.20
  20. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 7.0.0-34.34.1
  21. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 7.0.0-34.34.1

Event History

Aug 15, 2026
CVE Published
via MITRE·05:56 AM
Data Sourced
via MITRE·05:56 AM
DescriptionSeverity
Data Sourced
via OSV·06:22 AM
DescriptionSeverityAffected Software
Event
via OSV·06:22 AM
Data Sourced
via NVD·06:22 AM
DescriptionSeverity

Frequently Asked Questions

1

What is the severity of CVE-2026-72393?

CVE-2026-72393 has a risk rating of 55.

2

What type of vulnerability is CVE-2026-72393?

CVE-2026-72393 is classified as a Use After Free vulnerability.

3

How do I fix CVE-2026-72393?

To fix CVE-2026-72393, update to the latest version of the Linux kernel where this vulnerability is resolved.

4

What components are affected by CVE-2026-72393?

CVE-2026-72393 affects the 'fbnic' driver in the Linux kernel.

5

What are the consequences of CVE-2026-72393?

CVE-2026-72393 can lead to potential memory corruption and exploitation due to use-after-free scenarios.

Contact

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