Race condition in Linux kernel - CVE-2026-52977
Published: June 25, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a race condition in futex requeue-PI handling in kernel/futex/requeue.c when processing wait-requeue-pi and requeue-PI operations during signal or timeout wakeup. A local user can trigger concurrent futex operations to cause a denial of service.
The issue can result in a live lock where one task blocks on a hash bucket lock while another busy loops, potentially locking up the system.
Affected software
Ubuntu
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
How to mitigate CVE-2026-52977
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2, 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1, 7.0.0-1008.8, 7.0.0-1010.10
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1, 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - addressed in versions 6.8.0-1061.64+1, 7.0.0-1009.9, 7.0.0-1015.15
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1, 7.0.0-1009.9, 7.0.0-1010.10
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
External References
- https://git.kernel.org/stable/c/0304d60abb9dcc02bc7fe6d1850f4ca206e8f1a0
- https://git.kernel.org/stable/c/0aacb6d18f76552e3e0ee25d9f40d21b3486f4cf
- https://git.kernel.org/stable/c/4e0ed44e51727d56244a822ab941efe507c47966
- https://git.kernel.org/stable/c/69a7cfc66405aeaa2483147653d031b3592ffc9c
- https://git.kernel.org/stable/c/bc7304f3ae20972d11db6e0b1b541c63feda5f05
- https://git.kernel.org/stable/c/e3f95b1ba242e37093305812df7fdbe7288a43ac
Related Security Bulletins
- Race condition in Linux kernel futex
- Ubuntu update for linux-oem-7.0
- Ubuntu update for linux
- Ubuntu update for linux
- Ubuntu update for linux-gcp-fips
- Ubuntu update for linux-oracle-6.8
- Ubuntu update for linux-fips
- Ubuntu update for linux-ibm
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-azure
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws
- Ubuntu update for linux-hwe-6.8
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-ibm
- Ubuntu update for linux-aws
- Ubuntu update for linux-raspi
- Ubuntu update for linux-nvidia-bos
- Ubuntu update for linux-nvidia