CVE-2026-53264: net/sched: act_api: use RCU with deferred freeing for action lifecycle

Published Jun 25, 2026
·
Updated

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

net/sched: actapi: use RCU with deferred freeing for action lifecycle

When NEWTFILTER and DELFILTER are run concurrently it is possible to create a race with an associated action.

Let's illustrate with CPU0 running NEWTFILTER and CPU1 running DELFILTER:

0: mutexlock() <-- holds the idr lock 0: rcureadlock() 0: p = idrfind(idr, index) <-- action p is valid (RCU protects IDR) 0: mutexunlock() <-- releases the idr lock 1: refcountdecandmutexlock() <-- refcnt 1->0, mutex held 1: idrremove(idr, index) <-- Action removed from IDR 1: mutexunlock() <-- mutex released allowing us to delete the action 1: tcfactioncleanup(p); kfree(p) <-- Kfrees p immediately, no deferral 0: refcountincnotzero(&p->tcfarefcnt) <-- ouch, UAF p points to freed memory

This patch fixes the race condition between NEWTFILTER and DELFILTER by adding struct rcuhead to tcaction used in the deferral and introducing a callrcu() in the delete path to defer the final kfree().

Note: this is a revert of commit d7fb60b9cafb ("netsched: get rid of tcfarcu") but also modernization/simplification to directly use kfreercu().

Let's illustrate the new restored code path:

0: rcureadlock() 1: refcountdecandmutexlock() <-- refcnt 1->0, mutex held 1: idrremove(idr, index) 1: mutexunlock() 1: callrcu(&p->tcfarcu, tcfactionrcufree) <-- defer kfree after grace period 0: p = idrfind(idr, index) 0: refcountincnotzero(&p->tcfarefcnt) <-- fails, refcnt already 0 1: rcureadunlock() <-- release so freeing can run after grace period

After CPU1 calls idrremove(), the object is no longer reachable through the IDR. CPU0's subsequent idrfind() will return NULL, and even if it still held a stale pointer, the immediate kfree() is now deferred until after the RCU grace period, so no UAF can occur.

Affected Software

271 affected componentsFixes available
Linux Foundation Linux Kernel
Microsoft azl3 kernel 6.6.141.1-1<6.6.143.1-1
6.6.143.1-1
Linux Linux kernel>=4.14<5.10.259
Linux Linux kernel>=5.11<5.15.210
Linux Linux kernel>=5.16<6.1.176
Linux Linux kernel>=6.2<6.6.143
Linux Linux kernel>=6.7<6.12.94
Linux Linux kernel>=6.13<6.18.36
Linux Linux kernel>=6.19<7.0.13
Linux Linux kernel=7.1-rc1
Linux Linux kernel=7.1-rc2
Linux Linux kernel=7.1-rc3
Linux Linux kernel=7.1-rc4
Linux Linux kernel=7.1-rc5
Linux Linux kernel=7.1-rc6
ubuntu/linux-azure*
ubuntu/linux-aws-hwe*
ubuntu/linux-azure*
ubuntu/linux-gcp*
ubuntu/linux-hwe*
ubuntu/linux-hwe-edge*
ubuntu/linux-oracle*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-aws-5.4*
ubuntu/linux-azure*
ubuntu/linux-azure-4.15*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-5.4*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-4.15*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-5.4*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-5.4*
ubuntu/linux-hwe-edge*
ubuntu/linux-ibm-5.4*
ubuntu/linux-kvm*
ubuntu/linux-oem*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-oracle-5.4*
ubuntu/linux-raspi-5.4*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.15<5.15.0-1117.124~20.04.1
5.15.0-1117.124~20.04.1
ubuntu/linux-aws-5.8*
ubuntu/linux-azure*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15<5.15.0-1123.132~20.04.1
5.15.0-1123.132~20.04.1
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1122.131~20.04.1
5.15.0-1122.131~20.04.1
ubuntu/linux-bluefield*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15<5.15.0-1118.128~20.04.1
5.15.0-1118.128~20.04.1
ubuntu/linux-gcp-5.8*
ubuntu/linux-gke*
ubuntu/linux-gke-5.15*
ubuntu/linux-gkeop*
ubuntu/linux-gkeop-5.15*
ubuntu/linux-hwe-5.11*
ubuntu/linux-hwe-5.13*
ubuntu/linux-hwe-5.15<5.15.0-198.208~20.04.1
5.15.0-198.208~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm*
ubuntu/linux-ibm-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15<5.15.0-1112.118~20.04.1
5.15.0-1112.118~20.04.1
ubuntu/linux-iot*
ubuntu/linux-kvm*
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-195.205~20.04.1
5.15.0-195.205~20.04.1
ubuntu/linux-nvidia-tegra-5.15<5.15.0-1070.72~20.04.1
5.15.0-1070.72~20.04.1
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.15<5.15.0-1114.120~20.04.1
5.15.0-1114.120~20.04.1
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-riscv-5.8*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.15.0-198.208
5.15.0-198.208
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1117.124
5.15.0-1117.124
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8<6.8.0-1066.69~22.04.1
6.8.0-1066.69~22.04.1
ubuntu/linux-azure<5.15.0-1123.132
5.15.0-1123.132
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1070.78~22.04.1
6.8.0-1070.78~22.04.1
ubuntu/linux-azure-fde<5.15.0-1122.131
5.15.0-1122.131
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8<6.8.0-1068.75~22.04.1
6.8.0-1068.75~22.04.1
ubuntu/linux-gcp<5.15.0-1118.128
5.15.0-1118.128
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1070.78~22.04.1
6.8.0-1070.78~22.04.1
ubuntu/linux-gke<5.15.0-1113.119
5.15.0-1113.119
ubuntu/linux-gkeop<5.15.0-1100.108
5.15.0-1100.108
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm<5.15.0-1111.115
5.15.0-1111.115
ubuntu/linux-ibm-6.8<6.8.0-1066.67~22.04.1
6.8.0-1066.67~22.04.1
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1112.118
5.15.0-1112.118
ubuntu/linux-kvm<5.15.0-1109.114
5.15.0-1109.114
ubuntu/linux-lowlatency<5.15.0-195.205
5.15.0-195.205
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8<6.8.0-146.146.1~22.04.1
6.8.0-146.146.1~22.04.1
ubuntu/linux-nvidia<5.15.0-1112.113
5.15.0-1112.113
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1064.67~22.04.1
6.8.0-1064.67~22.04.1
ubuntu/linux-nvidia-tegra<5.15.0-1070.72
5.15.0-1070.72
ubuntu/linux-nvidia-tegra-igx<5.15.0-1059.59
5.15.0-1059.59
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1114.120
5.15.0-1114.120
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-146.146~22.04.1
6.8.0-146.146~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp<5.15.0-1080.84
5.15.0-1080.84
ubuntu/linux-bluefield<5.15.0-1101.103
5.15.0-1101.103
ubuntu/linux-intel-iot-realtime<5.15.0-1109.111
5.15.0-1109.111
ubuntu/linux-realtime<5.15.0-1116.125
5.15.0-1116.125
ubuntu/linux-realtime-6.8<6.8.1-1061.62~22.04.1
6.8.1-1061.62~22.04.1
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux-aws-fips<5.15.0-1117.124+fips1
5.15.0-1117.124+fips1
ubuntu/linux-azure-fips<5.15.0-1123.132+fips1
5.15.0-1123.132+fips1
ubuntu/linux-fips<5.15.0-198.208+fips1
5.15.0-198.208+fips1
ubuntu/linux-gcp-fips<5.15.0-1118.128+fips1
5.15.0-1118.128+fips1
ubuntu/linux<6.8.0-146.146
6.8.0-146.146
ubuntu/linux-aws<6.8.0-1066.69
6.8.0-1066.69
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-aws-7.0<7.0.0-1012.12~24.04.1
7.0.0-1012.12~24.04.1
ubuntu/linux-azure<6.8.0-1070.78
6.8.0-1070.78
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0<7.0.0-1014.14~24.04.1
7.0.0-1014.14~24.04.1
ubuntu/linux-azure-fde<6.8.0-1068.75
6.8.0-1068.75
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0<7.0.0-1013.13~24.04.1
7.0.0-1013.13~24.04.1
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1070.78
6.8.0-1070.78
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0<7.0.0-1011.11~24.04.1
7.0.0-1011.11~24.04.1
ubuntu/linux-gke<6.8.0-1065.73
6.8.0-1065.73
ubuntu/linux-gkeop<6.8.0-1051.55
6.8.0-1051.55
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-31.31~24.04.1
7.0.0-31.31~24.04.1
ubuntu/linux-ibm<6.8.0-1066.67
6.8.0-1066.67
ubuntu/linux-lowlatency<6.8.0-146.146.1
6.8.0-146.146.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1064.67
6.8.0-1064.67
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0<7.0.0-1018.18~24.04.1
7.0.0-1018.18~24.04.1
ubuntu/linux-nvidia-lowlatency<6.8.0-1064.67.1
6.8.0-1064.67.1
ubuntu/linux-nvidia-tegra<6.8.0-1035.38
6.8.0-1035.38
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1063.66
6.8.0-1063.66
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0<7.0.0-1011.11~24.04.1
7.0.0-1011.11~24.04.1
ubuntu/linux-raspi*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-31.31.1~24.04.1
7.0.0-31.31.1~24.04.1
ubuntu/linux-vmware<6.8.0-1008.8
6.8.0-1008.8
ubuntu/linux-xilinx*
ubuntu/linux-bluefield<6.8.0-1032.37
6.8.0-1032.37
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime<6.8.1-1061.62
6.8.1-1061.62
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips<6.8.0-1066.69+fips1
6.8.0-1066.69+fips1
ubuntu/linux-azure-fips<6.8.0-1069.77+fips1
6.8.0-1069.77+fips1
ubuntu/linux-fips<6.8.0-146.146+fips1
6.8.0-146.146+fips1
ubuntu/linux-gcp-fips<6.8.0-1070.78+fips1
6.8.0-1070.78+fips1
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-azure*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp*
ubuntu/linux-oracle*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux<7.0.0-31.31
7.0.0-31.31
ubuntu/linux-aws<7.0.0-1012.12
7.0.0-1012.12
ubuntu/linux-azure<7.0.0-1014.14
7.0.0-1014.14
ubuntu/linux-azure-fde<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-gcp<7.0.0-1011.11
7.0.0-1011.11
ubuntu/linux-gke<7.0.0-1006.7
7.0.0-1006.7
ubuntu/linux-ibm<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-nvidia<7.0.0-1018.18
7.0.0-1018.18
ubuntu/linux-nvidia-bos<7.0.0-2018.18
7.0.0-2018.18
ubuntu/linux-oem-7.0<7.0.0-1013.13
7.0.0-1013.13
ubuntu/linux-oracle<7.0.0-1011.11
7.0.0-1011.11
ubuntu/linux-raspi<7.0.0-1019.19
7.0.0-1019.19
ubuntu/linux-realtime<7.0.0-31.31.1
7.0.0-31.31.1
ubuntu/linux-riscv<7.0.0-31.31.1
7.0.0-31.31.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.143.1-1
  2. Upgrade

    Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124~20.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132~20.04.1
  4. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1122.131~20.04.1
  5. Upgrade

    Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128~20.04.1
  6. Upgrade

    Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208~20.04.1
  7. Upgrade

    Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  8. Upgrade

    Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.118~20.04.1
  9. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-195.205~20.04.1
  10. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1070.72~20.04.1
  11. Upgrade

    Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.120~20.04.1
  12. Upgrade

    Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115~20.04.1
  13. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208
  14. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124
  15. Upgrade

    Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.69~22.04.1
  16. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132
  17. Upgrade

    Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1070.78~22.04.1
  18. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 5.15.0-1122.131
  19. Upgrade

    Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1068.75~22.04.1
  20. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128
  21. Upgrade

    Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1070.78~22.04.1
  22. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 5.15.0-1113.119
  23. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 5.15.0-1100.108
  24. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.115
  25. Upgrade

    Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.67~22.04.1
  26. Upgrade

    Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.118
  27. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1109.114
  28. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 5.15.0-195.205
  29. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-146.146.1~22.04.1
  30. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.113
  31. Upgrade

    Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.67~22.04.1
  32. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 5.15.0-1070.72
  33. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.

    Fixed in 5.15.0-1059.59
  34. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 5.15.0-1114.120
  35. Upgrade

    Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-146.146~22.04.1
  36. Upgrade

    Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1080.84
  37. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 5.15.0-1101.103
  38. Upgrade

    Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1109.111
  39. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1116.125
  40. Upgrade

    Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.1-1061.62~22.04.1
  41. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.124+fips1
  42. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1123.132+fips1
  43. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-198.208+fips1
  44. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1118.128+fips1
  45. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.8.0-146.146
  46. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.69
  47. Upgrade

    Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1012.12~24.04.1
  48. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.8.0-1070.78
  49. Upgrade

    Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14~24.04.1
  50. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 6.8.0-1068.75
  51. Upgrade

    Upgrade ubuntu/linux-azure-fde-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13~24.04.1
  52. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.8.0-1070.78
  53. Upgrade

    Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1011.11~24.04.1
  54. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 6.8.0-1065.73
  55. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 6.8.0-1051.55
  56. Upgrade

    Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-31.31~24.04.1
  57. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.67
  58. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-146.146.1
  59. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.67
  60. Upgrade

    Upgrade ubuntu/linux-nvidia-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1018.18~24.04.1
  61. Upgrade

    Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.67.1
  62. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 6.8.0-1035.38
  63. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.8.0-1063.66
  64. Upgrade

    Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1011.11~24.04.1
  65. Upgrade

    Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-31.31.1~24.04.1
  66. Upgrade

    Upgrade ubuntu/linux-vmware to a version that resolves this vulnerability.

    Fixed in 6.8.0-1008.8
  67. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 6.8.0-1032.37
  68. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.1-1061.62
  69. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1066.69+fips1
  70. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1069.77+fips1
  71. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-146.146+fips1
  72. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1070.78+fips1
  73. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 7.0.0-31.31
  74. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 7.0.0-1012.12
  75. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 7.0.0-1014.14
  76. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  77. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 7.0.0-1011.11
  78. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 7.0.0-1006.7
  79. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  80. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 7.0.0-1018.18
  81. Upgrade

    Upgrade ubuntu/linux-nvidia-bos to a version that resolves this vulnerability.

    Fixed in 7.0.0-2018.18
  82. Upgrade

    Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.

    Fixed in 7.0.0-1013.13
  83. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 7.0.0-1011.11
  84. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 7.0.0-1019.19
  85. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 7.0.0-31.31.1
  86. Upgrade

    Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.

    Fixed in 7.0.0-31.31.1
  87. Upgrade

    Upgrade Linux kernel to a version that resolves this vulnerability.

    Patch net/sched: act_api: use RCU with deferred freeing for action lifecycle

Event History

Jun 25, 2026
CVE Published
via MITRE·08:39 AM
Data Sourced
via MITRE·08:39 AM
DescriptionSeverity
Data Sourced
via OSV·09:16 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·09:16 AM
RemedyDescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·10:09 AM
DescriptionSeverityAffected Software
Jun 27, 2026
Data Sourced
via Microsoft·08:08 AM
DescriptionSeverityWeaknessAffected Software
Jul 28, 2026
Exploit Published
09:15 AM

Frequently Asked Questions

1

What is the severity of CVE-2026-53264?

CVE-2026-53264 has a risk rating of 55, indicating a medium severity vulnerability.

2

How do I fix CVE-2026-53264?

To fix CVE-2026-53264, update your Linux kernel to the latest version where this vulnerability has been resolved.

3

What systems are affected by CVE-2026-53264?

CVE-2026-53264 affects the Linux Kernel when using the net/sched component with the NEWTFILTER and DELFILTER functionalities.

4

What type of vulnerability is CVE-2026-53264?

CVE-2026-53264 is classified as a race condition vulnerability within the Linux Kernel.

5

What can happen if CVE-2026-53264 is exploited?

Exploitation of CVE-2026-53264 can lead to unexpected behavior or system instability due to race conditions during action lifecycle management.

Contact

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