CVE-2026-72393: eth: fbnic: don't cache shinfo across skb realloc
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
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-34.34~24.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1012.12~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-34.34.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-34.34 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1007.8 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2022.23 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1012.12 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 7.0.0-1020.20 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-34.34.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-34.34.1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72393?
CVE-2026-72393 has a risk rating of 55.
What type of vulnerability is CVE-2026-72393?
CVE-2026-72393 is classified as a Use After Free vulnerability.
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.
What components are affected by CVE-2026-72393?
CVE-2026-72393 affects the 'fbnic' driver in the Linux kernel.
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.