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Vulnerability · Published Dec 9, 2025 · Assigned by Linux

CVE-2023-53815posix-timers: Prevent RT livelock in itimer_delete()

Unrated

In plain English

A security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 91.2% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: posix-timers: Prevent RT livelock in itimer_delete() itimer_delete() has a retry loop when the timer is concurrently expired. On non-RT kernels this just spin-waits until the timer callback has completed, except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK enabled. In that case and on RT kernels the existing task could live lock when preempting the task which does the timer delivery. Replace spin_unlock() with an invocation of timer_wait_running() to handle it the same way as the other retry loops in the posix timer code.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.52-1DEBIAN-CVE-2023-53815
Debian:13linux6.4.4-1DEBIAN-CVE-2023-53815
Debian:14linux6.4.4-1DEBIAN-CVE-2023-53815
Ubuntu:22.04:LTSlinux5.15.0-86.96UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-aws5.15.0-1047.52UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure5.15.0-1049.56UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1049.56.1UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-gcp5.15.0-1044.52UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-gke5.15.0-1044.49UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1030.35UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-ibm5.15.0-1040.43UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1043.49UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-kvm5.15.0-1044.49UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-86.95UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1037.37UBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1018.18UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1005.5UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-oracle5.15.0-1045.51UBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-raspi5.15.0-1040.43UBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2023-53815
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1025.29UBUNTU-CVE-2023-53815

Affected products (as reported)

VendorProductVersions
Linux Linux ec8f954a40da8cd3d159713b608e901f0cd909a9 – before f1be1ed32daa053484222f7f9beb2b16c624dffdec8f954a40da8cd3d159713b608e901f0cd909a9 – before 0670c4c567b27bd8f999a943028f4fe60d1a1106ec8f954a40da8cd3d159713b608e901f0cd909a9 – before e7aff15ba29ba4b3052786b1636fa5c4aa39e179ec8f954a40da8cd3d159713b608e901f0cd909a9 – before f9bd298e3e4d3fd6e19f017789a42d0f332cd555ec8f954a40da8cd3d159713b608e901f0cd909a9 – before c1968bb8a28625cc95d2ad3ca872ab98c9c36d59ec8f954a40da8cd3d159713b608e901f0cd909a9 – before 9d9e522010eb5685d8b53e8a24320653d9d4cbbf
Linux Linux 5.4

References