CVE Vulnerabilities

CVE-2026-63802

Use After Free

Published: Jul 19, 2026 | Modified: Aug 17, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
7 MODERATE
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM
root.io logo minimus.io logo echo.ai logo

In the Linux kernel, the following vulnerability has been resolved:

blk-cgroup: fix UAF in __blkcg_rstat_flush()

When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkgs __blkcg_rstat_flush() removes another blkgs iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries.

Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flushs rcu_read_lock() section to complete before freeing.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

NameVendorStart VersionEnd Version
Linux_kernelLinux6.3.9 (including)6.4 (excluding)
Linux_kernelLinux6.4.1 (including)6.6.144 (excluding)
Linux_kernelLinux6.7 (including)6.12.95 (excluding)
Linux_kernelLinux6.13 (including)6.18.38 (excluding)
Linux_kernelLinux6.19 (including)7.1.3 (excluding)
Linux_kernelLinux6.4 (including)6.4 (including)
Linux_kernelLinux6.4-rc7 (including)6.4-rc7 (including)
Red Hat Enterprise Linux 10RedHatkernel-0:6.12.0-211.59.1.el10_2*
Red Hat Enterprise Linux 8RedHatkernel-rt-0:4.18.0-553.163.1.rt7.504.el8_10*
Red Hat Enterprise Linux 8RedHatkernel-0:4.18.0-553.163.1.el8_10*
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRedHatkernel-0:4.18.0-372.221.1.el8_6*
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnRedHatkernel-0:4.18.0-372.221.1.el8_6*
Red Hat Enterprise Linux 9RedHatkernel-0:5.14.0-687.51.1.el9_8*
Red Hat Enterprise Linux 9RedHatkernel-0:5.14.0-687.51.1.el9_8*
LinuxUbuntunoble*
LinuxUbunturesolute*
LinuxUbuntuupstream*
Linux-allwinner-5.19Ubuntujammy*
Linux-allwinner-5.19Ubuntuupstream*
Linux-awsUbuntunoble*
Linux-awsUbunturesolute*
Linux-awsUbuntuupstream*
Linux-aws-5.0Ubuntubionic*
Linux-aws-5.0Ubuntuesm-infra/bionic*
Linux-aws-5.0Ubuntuupstream*
Linux-aws-5.11Ubuntuesm-infra/focal*
Linux-aws-5.11Ubuntufocal*
Linux-aws-5.11Ubuntuupstream*
Linux-aws-5.13Ubuntuesm-infra/focal*
Linux-aws-5.13Ubuntufocal*
Linux-aws-5.13Ubuntuupstream*
Linux-aws-5.15Ubuntuupstream*
Linux-aws-5.19Ubuntujammy*
Linux-aws-5.19Ubuntuupstream*
Linux-aws-5.3Ubuntubionic*
Linux-aws-5.3Ubuntuesm-infra/bionic*
Linux-aws-5.3Ubuntuupstream*
Linux-aws-5.4Ubuntuupstream*
Linux-aws-5.8Ubuntuesm-infra/focal*
Linux-aws-5.8Ubuntufocal*
Linux-aws-5.8Ubuntuupstream*
Linux-aws-6.14Ubuntunoble*
Linux-aws-6.14Ubuntuupstream*
Linux-aws-6.17Ubuntunoble*
Linux-aws-6.17Ubuntuupstream*
Linux-aws-6.2Ubuntujammy*
Linux-aws-6.2Ubuntuupstream*
Linux-aws-6.5Ubuntujammy*
Linux-aws-6.5Ubuntuupstream*
Linux-aws-6.8Ubuntujammy*
Linux-aws-6.8Ubuntuupstream*
Linux-aws-7.0Ubuntunoble*
Linux-aws-7.0Ubuntuupstream*
Linux-aws-fipsUbuntufips-updates/noble*
Linux-aws-fipsUbuntuupstream*
Linux-aws-hweUbuntuupstream*
Linux-azureUbuntubionic*
Linux-azureUbuntuesm-infra/bionic*
Linux-azureUbuntunoble*
Linux-azureUbunturesolute*
Linux-azureUbuntuupstream*
Linux-azure-4.15Ubuntuupstream*
Linux-azure-5.11Ubuntuesm-infra/focal*
Linux-azure-5.11Ubuntufocal*
Linux-azure-5.11Ubuntuupstream*
Linux-azure-5.13Ubuntuesm-infra/focal*
Linux-azure-5.13Ubuntufocal*
Linux-azure-5.13Ubuntuupstream*
Linux-azure-5.15Ubuntuupstream*
Linux-azure-5.19Ubuntujammy*
Linux-azure-5.19Ubuntuupstream*
Linux-azure-5.3Ubuntubionic*
Linux-azure-5.3Ubuntuesm-infra/bionic*
Linux-azure-5.3Ubuntuupstream*
Linux-azure-5.4Ubuntuupstream*
Linux-azure-5.8Ubuntuesm-infra/focal*
Linux-azure-5.8Ubuntufocal*
Linux-azure-5.8Ubuntuupstream*
Linux-azure-6.11Ubuntunoble*
Linux-azure-6.11Ubuntuupstream*
Linux-azure-6.14Ubuntunoble*
Linux-azure-6.14Ubuntuupstream*
Linux-azure-6.17Ubuntunoble*
Linux-azure-6.17Ubuntuupstream*
Linux-azure-6.2Ubuntujammy*
Linux-azure-6.2Ubuntuupstream*
Linux-azure-6.5Ubuntujammy*
Linux-azure-6.5Ubuntuupstream*
Linux-azure-6.8Ubuntujammy*
Linux-azure-6.8Ubuntuupstream*
Linux-azure-7.0Ubuntunoble*
Linux-azure-7.0Ubuntuupstream*
Linux-azure-edgeUbuntubionic*
Linux-azure-edgeUbuntuesm-infra/bionic*
Linux-azure-edgeUbuntuupstream*
Linux-azure-fdeUbuntuesm-infra/focal*
Linux-azure-fdeUbuntufocal*
Linux-azure-fdeUbuntunoble*
Linux-azure-fdeUbunturesolute*
Linux-azure-fdeUbuntuupstream*
Linux-azure-fde-5.15Ubuntuupstream*
Linux-azure-fde-5.19Ubuntujammy*
Linux-azure-fde-5.19Ubuntuupstream*
Linux-azure-fde-6.14Ubuntunoble*
Linux-azure-fde-6.14Ubuntuupstream*
Linux-azure-fde-6.17Ubuntunoble*
Linux-azure-fde-6.17Ubuntuupstream*
Linux-azure-fde-6.2Ubuntujammy*
Linux-azure-fde-6.2Ubuntuupstream*
Linux-azure-fde-6.8Ubuntujammy*
Linux-azure-fde-6.8Ubuntuupstream*
Linux-azure-fde-7.0Ubuntunoble*
Linux-azure-fde-7.0Ubuntuupstream*
Linux-azure-fipsUbuntufips-updates/noble*
Linux-azure-fipsUbuntuupstream*
Linux-azure-nvidiaUbuntunoble*
Linux-azure-nvidiaUbuntuupstream*
Linux-azure-nvidia-6.14Ubuntunoble*
Linux-azure-nvidia-6.14Ubuntuupstream*
Linux-bluefieldUbuntubluefield/noble*
Linux-bluefieldUbuntuupstream*
Linux-fipsUbuntufips-updates/noble*
Linux-fipsUbuntuupstream*
Linux-gcpUbuntubionic*
Linux-gcpUbuntuesm-infra/bionic*
Linux-gcpUbuntunoble*
Linux-gcpUbunturesolute*
Linux-gcpUbuntuupstream*
Linux-gcp-4.15Ubuntuupstream*
Linux-gcp-5.11Ubuntuesm-infra/focal*
Linux-gcp-5.11Ubuntufocal*
Linux-gcp-5.11Ubuntuupstream*
Linux-gcp-5.13Ubuntuesm-infra/focal*
Linux-gcp-5.13Ubuntufocal*
Linux-gcp-5.13Ubuntuupstream*
Linux-gcp-5.15Ubuntuupstream*
Linux-gcp-5.19Ubuntujammy*
Linux-gcp-5.19Ubuntuupstream*
Linux-gcp-5.3Ubuntubionic*
Linux-gcp-5.3Ubuntuesm-infra/bionic*
Linux-gcp-5.3Ubuntuupstream*
Linux-gcp-5.4Ubuntuupstream*
Linux-gcp-5.8Ubuntuesm-infra/focal*
Linux-gcp-5.8Ubuntufocal*
Linux-gcp-5.8Ubuntuupstream*
Linux-gcp-6.11Ubuntunoble*
Linux-gcp-6.11Ubuntuupstream*
Linux-gcp-6.14Ubuntunoble*
Linux-gcp-6.14Ubuntuupstream*
Linux-gcp-6.17Ubuntunoble*
Linux-gcp-6.17Ubuntuupstream*
Linux-gcp-6.2Ubuntujammy*
Linux-gcp-6.2Ubuntuupstream*
Linux-gcp-6.5Ubuntujammy*
Linux-gcp-6.5Ubuntuupstream*
Linux-gcp-6.8Ubuntujammy*
Linux-gcp-6.8Ubuntuupstream*
Linux-gcp-7.0Ubuntunoble*
Linux-gcp-7.0Ubuntuupstream*
Linux-gcp-fipsUbuntufips-updates/noble*
Linux-gcp-fipsUbuntuupstream*
Linux-gkeUbuntuesm-infra/focal*
Linux-gkeUbuntufocal*
Linux-gkeUbuntunoble*
Linux-gkeUbunturesolute*
Linux-gkeUbuntuupstream*
Linux-gkeUbuntuxenial*
Linux-gke-4.15Ubuntubionic*
Linux-gke-4.15Ubuntuesm-infra/bionic*
Linux-gke-4.15Ubuntuupstream*
Linux-gke-5.15Ubuntuesm-infra/focal*
Linux-gke-5.15Ubuntufocal*
Linux-gke-5.15Ubuntuupstream*
Linux-gke-5.4Ubuntubionic*
Linux-gke-5.4Ubuntuesm-infra/bionic*
Linux-gke-5.4Ubuntuupstream*
Linux-gkeopUbuntuesm-infra/focal*
Linux-gkeopUbuntufocal*
Linux-gkeopUbuntunoble*
Linux-gkeopUbuntuupstream*
Linux-gkeop-5.15Ubuntuesm-infra/focal*
Linux-gkeop-5.15Ubuntufocal*
Linux-gkeop-5.15Ubuntuupstream*
Linux-gkeop-5.4Ubuntubionic*
Linux-gkeop-5.4Ubuntuesm-infra/bionic*
Linux-gkeop-5.4Ubuntuupstream*
Linux-hweUbuntubionic*
Linux-hweUbuntuesm-infra/bionic*
Linux-hweUbuntuupstream*
Linux-hwe-5.11Ubuntuesm-infra/focal*
Linux-hwe-5.11Ubuntufocal*
Linux-hwe-5.11Ubuntuupstream*
Linux-hwe-5.13Ubuntuesm-infra/focal*
Linux-hwe-5.13Ubuntufocal*
Linux-hwe-5.13Ubuntuupstream*
Linux-hwe-5.15Ubuntuupstream*
Linux-hwe-5.19Ubuntujammy*
Linux-hwe-5.19Ubuntuupstream*
Linux-hwe-5.4Ubuntuupstream*
Linux-hwe-5.8Ubuntuesm-infra/focal*
Linux-hwe-5.8Ubuntufocal*
Linux-hwe-5.8Ubuntuupstream*
Linux-hwe-6.11Ubuntunoble*
Linux-hwe-6.11Ubuntuupstream*
Linux-hwe-6.14Ubuntunoble*
Linux-hwe-6.14Ubuntuupstream*
Linux-hwe-6.17Ubuntunoble*
Linux-hwe-6.17Ubuntuupstream*
Linux-hwe-6.2Ubuntujammy*
Linux-hwe-6.2Ubuntuupstream*
Linux-hwe-6.5Ubuntujammy*
Linux-hwe-6.5Ubuntuupstream*
Linux-hwe-6.8Ubuntujammy*
Linux-hwe-6.8Ubuntuupstream*
Linux-hwe-7.0Ubuntunoble*
Linux-hwe-7.0Ubuntuupstream*
Linux-hwe-edgeUbuntubionic*
Linux-hwe-edgeUbuntuesm-infra-legacy/xenial*
Linux-hwe-edgeUbuntuesm-infra/bionic*
Linux-hwe-edgeUbuntuesm-infra/xenial*
Linux-hwe-edgeUbuntuupstream*
Linux-hwe-edgeUbuntuxenial*
Linux-ibmUbuntunoble*
Linux-ibmUbunturesolute*
Linux-ibmUbuntuupstream*
Linux-ibm-5.15Ubuntuupstream*
Linux-ibm-5.4Ubuntuupstream*
Linux-ibm-6.8Ubuntujammy*
Linux-ibm-6.8Ubuntuupstream*
Linux-intel-5.13Ubuntuesm-infra/focal*
Linux-intel-5.13Ubuntufocal*
Linux-intel-5.13Ubuntuupstream*
Linux-intel-iot-realtimeUbuntujammy*
Linux-intel-iot-realtimeUbuntuupstream*
Linux-intel-iotgUbuntuupstream*
Linux-intel-iotg-5.15Ubuntuupstream*
Linux-iotUbuntuupstream*
Linux-kvmUbuntuupstream*
Linux-lowlatencyUbuntunoble*
Linux-lowlatencyUbuntuupstream*
Linux-lowlatency-hwe-5.15Ubuntuupstream*
Linux-lowlatency-hwe-5.19Ubuntujammy*
Linux-lowlatency-hwe-5.19Ubuntuupstream*
Linux-lowlatency-hwe-6.11Ubuntunoble*
Linux-lowlatency-hwe-6.11Ubuntuupstream*
Linux-lowlatency-hwe-6.2Ubuntujammy*
Linux-lowlatency-hwe-6.2Ubuntuupstream*
Linux-lowlatency-hwe-6.5Ubuntujammy*
Linux-lowlatency-hwe-6.5Ubuntuupstream*
Linux-lowlatency-hwe-6.8Ubuntujammy*
Linux-lowlatency-hwe-6.8Ubuntuupstream*
Linux-lts-xenialUbuntuupstream*
Linux-nvidiaUbuntunoble*
Linux-nvidiaUbunturesolute*
Linux-nvidiaUbuntuupstream*
Linux-nvidia-6.11Ubuntunoble*
Linux-nvidia-6.11Ubuntuupstream*
Linux-nvidia-6.17Ubuntunoble*
Linux-nvidia-6.17Ubuntuupstream*
Linux-nvidia-6.2Ubuntujammy*
Linux-nvidia-6.2Ubuntuupstream*
Linux-nvidia-6.5Ubuntujammy*
Linux-nvidia-6.5Ubuntuupstream*
Linux-nvidia-6.8Ubuntujammy*
Linux-nvidia-6.8Ubuntuupstream*
Linux-nvidia-7.0Ubuntunoble*
Linux-nvidia-7.0Ubuntuupstream*
Linux-nvidia-bosUbunturesolute*
Linux-nvidia-bosUbuntuupstream*
Linux-nvidia-lowlatencyUbuntunoble*
Linux-nvidia-lowlatencyUbuntuupstream*
Linux-nvidia-tegraUbuntunoble*
Linux-nvidia-tegraUbuntuupstream*
Linux-nvidia-tegra-5.15Ubuntuupstream*
Linux-nvidia-tegra-igxUbuntuupstream*
Linux-oemUbuntubionic*
Linux-oemUbuntuesm-infra/bionic*
Linux-oemUbuntuupstream*
Linux-oemUbuntuxenial*
Linux-oem-5.10Ubuntuesm-infra/focal*
Linux-oem-5.10Ubuntufocal*
Linux-oem-5.10Ubuntuupstream*
Linux-oem-5.13Ubuntuesm-infra/focal*
Linux-oem-5.13Ubuntufocal*
Linux-oem-5.13Ubuntuupstream*
Linux-oem-5.14Ubuntuesm-infra/focal*
Linux-oem-5.14Ubuntufocal*
Linux-oem-5.14Ubuntuupstream*
Linux-oem-5.17Ubuntujammy*
Linux-oem-5.17Ubuntuupstream*
Linux-oem-5.6Ubuntuesm-infra/focal*
Linux-oem-5.6Ubuntufocal*
Linux-oem-5.6Ubuntuupstream*
Linux-oem-6.0Ubuntujammy*
Linux-oem-6.0Ubuntuupstream*
Linux-oem-6.1Ubuntujammy*
Linux-oem-6.1Ubuntuupstream*
Linux-oem-6.11Ubuntunoble*
Linux-oem-6.11Ubuntuupstream*
Linux-oem-6.14Ubuntunoble*
Linux-oem-6.14Ubuntuupstream*
Linux-oem-6.17Ubuntunoble*
Linux-oem-6.17Ubuntuupstream*
Linux-oem-6.5Ubuntujammy*
Linux-oem-6.5Ubuntuupstream*
Linux-oem-6.8Ubuntunoble*
Linux-oem-6.8Ubuntuupstream*
Linux-oem-7.0Ubunturesolute*
Linux-oem-7.0Ubuntuupstream*
Linux-oracleUbuntunoble*
Linux-oracleUbunturesolute*
Linux-oracleUbuntuupstream*
Linux-oracle-5.0Ubuntubionic*
Linux-oracle-5.0Ubuntuesm-infra/bionic*
Linux-oracle-5.0Ubuntuupstream*
Linux-oracle-5.11Ubuntuesm-infra/focal*
Linux-oracle-5.11Ubuntufocal*
Linux-oracle-5.11Ubuntuupstream*
Linux-oracle-5.13Ubuntuesm-infra/focal*
Linux-oracle-5.13Ubuntufocal*
Linux-oracle-5.13Ubuntuupstream*
Linux-oracle-5.15Ubuntuupstream*
Linux-oracle-5.3Ubuntubionic*
Linux-oracle-5.3Ubuntuesm-infra/bionic*
Linux-oracle-5.3Ubuntuupstream*
Linux-oracle-5.4Ubuntuupstream*
Linux-oracle-5.8Ubuntuesm-infra/focal*
Linux-oracle-5.8Ubuntufocal*
Linux-oracle-5.8Ubuntuupstream*
Linux-oracle-6.14Ubuntunoble*
Linux-oracle-6.14Ubuntuupstream*
Linux-oracle-6.17Ubuntunoble*
Linux-oracle-6.17Ubuntuupstream*
Linux-oracle-6.5Ubuntujammy*
Linux-oracle-6.5Ubuntuupstream*
Linux-oracle-6.8Ubuntujammy*
Linux-oracle-6.8Ubuntuupstream*
Linux-oracle-7.0Ubuntunoble*
Linux-oracle-7.0Ubuntuupstream*
Linux-raspiUbuntunoble*
Linux-raspiUbunturesolute*
Linux-raspiUbuntuupstream*
Linux-raspi-5.4Ubuntuupstream*
Linux-raspi-realtimeUbuntunoble*
Linux-raspi-realtimeUbunturealtime/noble*
Linux-raspi-realtimeUbuntuupstream*
Linux-raspi2Ubuntubionic*
Linux-raspi2Ubuntuesm-infra/focal*
Linux-raspi2Ubuntufocal*
Linux-raspi2Ubuntuupstream*
Linux-raspi2Ubuntuxenial*
Linux-realtimeUbuntujammy*
Linux-realtimeUbuntunoble*
Linux-realtimeUbunturealtime/noble*
Linux-realtimeUbunturesolute*
Linux-realtimeUbuntuupstream*
Linux-realtime-6.14Ubunturealtime/noble*
Linux-realtime-6.14Ubuntuupstream*
Linux-realtime-6.17Ubunturealtime/noble*
Linux-realtime-6.17Ubuntuupstream*
Linux-realtime-6.8Ubunturealtime/jammy*
Linux-realtime-6.8Ubuntuupstream*
Linux-riscvUbuntuesm-infra/focal*
Linux-riscvUbuntufocal*
Linux-riscvUbuntujammy*
Linux-riscvUbuntunoble*
Linux-riscvUbunturesolute*
Linux-riscvUbuntuupstream*
Linux-riscv-5.11Ubuntuesm-infra/focal*
Linux-riscv-5.11Ubuntufocal*
Linux-riscv-5.11Ubuntuupstream*
Linux-riscv-5.15Ubuntuupstream*
Linux-riscv-5.19Ubuntujammy*
Linux-riscv-5.19Ubuntuupstream*
Linux-riscv-5.8Ubuntuesm-infra/focal*
Linux-riscv-5.8Ubuntufocal*
Linux-riscv-5.8Ubuntuupstream*
Linux-riscv-6.14Ubuntunoble*
Linux-riscv-6.14Ubuntuupstream*
Linux-riscv-6.17Ubuntunoble*
Linux-riscv-6.17Ubuntuupstream*
Linux-riscv-6.5Ubuntujammy*
Linux-riscv-6.5Ubuntuupstream*
Linux-riscv-6.8Ubuntujammy*
Linux-riscv-6.8Ubuntuupstream*
Linux-riscv-7.0Ubuntunoble*
Linux-riscv-7.0Ubuntuupstream*
Linux-starfive-5.19Ubuntujammy*
Linux-starfive-5.19Ubuntuupstream*
Linux-starfive-6.2Ubuntujammy*
Linux-starfive-6.2Ubuntuupstream*
Linux-starfive-6.5Ubuntujammy*
Linux-starfive-6.5Ubuntuupstream*
Linux-xilinxUbuntunoble*
Linux-xilinxUbuntuupstream*
Linux-xilinx-zynqmpUbuntuupstream*

Potential Mitigations

References