Excessive Iteration in Linux kernel - CVE-2026-98644

Vulnerability identifier: #VU156957

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98644

CWE-ID: CWE-834

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service by triggering prolonged CPU stalls and soft lockups.

The vulnerability exists due to excessive iteration without rescheduling points in __htab_map_lookup_and_delete_batch() when processing BPF hash map batch operations. A local user can invoke batch lookups on a sufficiently large map to cause prolonged CPU stalls, because the batch count limits entries copied rather than buckets visited, and consecutive empty buckets are traversed within a single RCU read-side, instrumentation-disabled critical section.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/44f9bcb5ab2b268bc763ed3ebec83308b4972936
• https://git.kernel.org/stable/c/4e48fe9b1c77966bede0a73feb3059d7595f642d
• https://git.kernel.org/stable/c/5c8b1869cb99a32a962388848cd19604fb41263e
• https://git.kernel.org/stable/c/77a3b52b4455e6377e549539e757bc55eedefb51
• https://git.kernel.org/stable/c/85136bf22404474a815fc0ed26ec0d1cbc1bc3f9
• https://git.kernel.org/stable/c/ca5bd55fc508fbb5c08c62206d02237a5b6fc7e8
• https://git.kernel.org/stable/c/f0c09de08ec077098b7e1563f2285f1c136cd816

• Excessive Iteration in Linux kernel bpf
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more