Function Call with Incorrectly Specified Arguments in Linux kernel - CVE-2026-98934
Published: October 23, 2026
Vulnerability details
The vulnerability allows a local privileged user to trigger a kernel warning and potentially disrupt system availability.
The vulnerability exists due to failure to supply a required network namespace pointer in seg6_make_flowlabel() when computing flow hashes for packets without an associated device or socket. A local privileged user can trigger transmission of a TIPC UDP bearer discovery message through the affected path to provoke a warning in __skb_flow_dissect(), potentially disrupting system availability.
The reported trigger requires an IPv4 route using segment routing encapsulation and net.ipv6.seg6_flowlabel set to 1.
Affected software
Ubuntu
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-realtime (Ubuntu package)
linux-lowlatency-hwe-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-gke (Ubuntu package)
linux-vmware (Ubuntu package)
linux-ibm-6.8 (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure-fde-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
How to mitigate CVE-2026-98934
linux (Ubuntu package) - addressed in versions 6.8.0-149.149, 7.0.0-43.43
linux-lowlatency (Ubuntu package) - update to 6.8.0-149.149.1
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1068.72, 7.0.0-1023.23
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1073.82, 7.0.0-1020.21
linux-gcp (Ubuntu package) - addressed in versions 6.8.0-1073.81, 7.0.0-1017.19
linux-aws (Ubuntu package) - addressed in versions 6.8.0-1069.74, 7.0.0-1017.18
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1069.70, 7.0.0-1018.18
linux-oracle (Ubuntu package) - addressed in versions 6.8.0-1067.71, 7.0.0-1016.18
linux-nvidia (Ubuntu package) - update to 6.8.0-1067.70
linux-realtime (Ubuntu package) - addressed in versions 6.8.1-1064.65, 7.0.0-43.43.1
linux-lowlatency-hwe-6.8 (Ubuntu package) - update to 6.8.0-149.149.1~22.04.1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1071.78~22.04.1
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1073.82~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1067.71~22.04.1
linux-aws-6.8 (Ubuntu package) - update to 6.8.0-1069.74~22.04.1
linux-gkeop (Ubuntu package) - update to 6.8.0-1053.57
linux-gke (Ubuntu package) - addressed in versions 6.8.0-1068.77, 7.0.0-1010.11
linux-vmware (Ubuntu package) - update to 6.8.0-1010.10
linux-ibm-6.8 (Ubuntu package) - update to 6.8.0-1069.70~22.04.1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1073.81~22.04.1
linux-aws-fips (Ubuntu package) - update to 6.8.0-1069.74+fips1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1073.81+fips1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1073.82+fips1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2056.58
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1064.65~22.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1016.18~24.04.1
linux-azure-fde-7.0 (Ubuntu package) - update to 7.0.0-1019.19~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1017.19~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1018.18
linux-azure-fde (Ubuntu package) - update to 7.0.0-1019.19
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1017.18~24.04.1
External References
- https://git.kernel.org/stable/c/086e8acb3a0e55f6d22d29fae2a4a3b1561bb766
- https://git.kernel.org/stable/c/4ab37e4f4a33c64d9e565dc8c4c3ed774f05c0e3
- https://git.kernel.org/stable/c/53b21bc2df6e8ed538bceda93a5104a5fe6a8a84
- https://git.kernel.org/stable/c/8ec454dcd00ce3375119111c6394964455b36d0d
- https://git.kernel.org/stable/c/8fe3d6717f5536793727e60b7a0b7ec20c697def
Related Security Bulletins
- Function Call with Incorrectly Specified Arguments in Linux kernel ipv6
- Ubuntu update for linux, linux-aws, linux-gcp and more
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0 and more
- Ubuntu update for linux-aws-fips, linux-gcp-fips, linux-gkeop and more
- Ubuntu update for linux-azure-6.8, linux-azure-fde-6.8
- Ubuntu update for linux-oracle-6.8, linux-raspi, linux-raspi-realtime
- Ubuntu update for linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8 and more
- Ubuntu update for linux, linux-aws, linux-azure and more
- Ubuntu update for linux-raspi