CVE-2025-21647: sched: sch_cake: add bounds checks to host bulk flow fairness counts

Published Jan 19, 2025
·
Updated

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

sched: schcake: add bounds checks to host bulk flow fairness counts

Even though we fixed a logic error in the commit cited below, syzbot still managed to trigger an underflow of the per-host bulk flow counters, leading to an out of bounds memory access.

To avoid any such logic errors causing out of bounds memory accesses, this commit factors out all accesses to the per-host bulk flow counters to a series of helpers that perform bounds-checking before any increments and decrements. This also has the benefit of improving readability by moving the conditional checks for the flow mode into these helpers, instead of having them spread out throughout the code (which was the cause of the original logic error).

As part of this change, the flow quantum calculation is consolidated into a helper function, which means that the dithering applied to the ost load scaling is now applied both in the DRR rotation and when a sparse flow's quantum is first initiated. The only user-visible effect of this is that the maximum packet size that can be sent while a flow stays sparse will now vary with +/- one byte in some cases. This should not make a noticeable difference in practice, and thus it's not worth complicating the code to preserve the old behaviour.

Other sources

This CVE was automatically created from a reference found in an email or other text. If you are reading this, then this CVE entry is probably erroneous, since this text should be replaced by the official CVE description automatically.

— Launchpad

Affected Software

190 affected componentsFixes available
Linux Linux kernel
IBM Verify Identity Access<=11.0 - 11.0.2
IBM Security Verify Access<=10.0 - 10.0.9.1
IBM Verify Identity Access Container<=11.0 - 11.0.2
IBM Security Verify Access Container<=10.0 - 10.0.9.1
Linux Linux kernel>=5.4.284<5.4.291
Linux Linux kernel>=5.10.226<5.10.235
Linux Linux kernel>=5.15.167<5.15.179
Linux Linux kernel>=6.1.110<6.1.125
Linux Linux kernel>=6.6.51<6.6.72
Linux Linux kernel>=6.10.10<6.11
Linux Linux kernel>=6.11.1<6.12.10
Linux Linux kernel=6.11
Linux Linux kernel=6.11-rc7
Linux Linux kernel=6.13-rc1
Linux Linux kernel=6.13-rc2
Linux Linux kernel=6.13-rc3
Linux Linux kernel=6.13-rc4
Linux Linux kernel=6.13-rc5
Linux Linux kernel=6.13-rc6
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-aws-5.4<5.4.0-1146.156~18.04.1
5.4.0-1146.156~18.04.1
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-5.4<5.4.0-1151.158~18.04.1
5.4.0-1151.158~18.04.1
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-5.4<5.4.0-1149.158~18.04.1
5.4.0-1149.158~18.04.1
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-5.4<5.4.0-216.236~18.04.1
5.4.0-216.236~18.04.1
ubuntu/linux-hwe-edge*
ubuntu/linux-ibm-5.4<5.4.0-1092.97~18.04.1
5.4.0-1092.97~18.04.1
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-oracle-5.4<5.4.0-1144.154~18.04.1
5.4.0-1144.154~18.04.1
ubuntu/linux-raspi-5.4<5.4.0-1129.142~18.04.1
5.4.0-1129.142~18.04.1
ubuntu/linux<5.4.0-216.236
5.4.0-216.236
ubuntu/linux-aws<5.4.0-1146.156
5.4.0-1146.156
ubuntu/linux-aws-5.15<5.15.0-1084.91~20.04.1
5.15.0-1084.91~20.04.1
ubuntu/linux-azure<5.4.0-1151.158
5.4.0-1151.158
ubuntu/linux-azure-5.15<5.15.0-1089.98~20.04.1
5.15.0-1089.98~20.04.1
ubuntu/linux-bluefield<5.4.0-1105.112
5.4.0-1105.112
ubuntu/linux-gcp<5.4.0-1149.158
5.4.0-1149.158
ubuntu/linux-gcp-5.15<5.15.0-1083.92~20.04.1
5.15.0-1083.92~20.04.1
ubuntu/linux-ibm<5.4.0-1092.97
5.4.0-1092.97
ubuntu/linux-ibm-5.15<5.15.0-1076.79~20.04.1
5.15.0-1076.79~20.04.1
ubuntu/linux-intel-iotg-5.15<5.15.0-1079.85~20.04.1
5.15.0-1079.85~20.04.1
ubuntu/linux-kvm<5.4.0-1133.142
5.4.0-1133.142
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-140.150~20.04.1
5.15.0-140.150~20.04.1
ubuntu/linux-oracle<5.4.0-1144.154
5.4.0-1144.154
ubuntu/linux-oracle-5.15<5.15.0-1081.87~20.04.1
5.15.0-1081.87~20.04.1
ubuntu/linux-raspi<5.4.0-1129.142
5.4.0-1129.142
ubuntu/linux-riscv-5.15<5.15.0-1079.83~20.04.1
5.15.0-1079.83~20.04.1
ubuntu/linux-xilinx-zynqmp<5.4.0-1064.68
5.4.0-1064.68
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.8*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
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<5.15.0-142.152~20.04.1
5.15.0-142.152~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-intel-5.13*
ubuntu/linux-iot<5.4.0-1051.54
5.4.0-1051.54
ubuntu/linux-nvidia-tegra-5.15<5.15.0-1039.39~20.04.1
5.15.0-1039.39~20.04.1
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.8*
ubuntu/linux-aws-fips<5.4.0-1146.156+fips1
5.4.0-1146.156+fips1
ubuntu/linux-azure-fips<5.4.0-1151.158+fips1
5.4.0-1151.158+fips1
ubuntu/linux-fips<5.4.0-1120.130
5.4.0-1120.130
ubuntu/linux-gcp-fips<5.4.0-1149.158+fips1
5.4.0-1149.158+fips1
ubuntu/linux<5.15.0-140.150
5.15.0-140.150
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1084.91
5.15.0-1084.91
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8<6.8.0-1029.31~22.04.1
6.8.0-1029.31~22.04.1
ubuntu/linux-azure<5.15.0-1089.98
5.15.0-1089.98
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1029.34~22.04.1
6.8.0-1029.34~22.04.1
ubuntu/linux-azure-fde<5.15.0-1089.98.1
5.15.0-1089.98.1
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-gcp<5.15.0-1083.92
5.15.0-1083.92
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1030.32~22.04.1
6.8.0-1030.32~22.04.1
ubuntu/linux-gke<5.15.0-1081.87
5.15.0-1081.87
ubuntu/linux-gkeop<5.15.0-1066.74
5.15.0-1066.74
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-hwe-6.8<6.8.0-60.63~22.04.1
6.8.0-60.63~22.04.1
ubuntu/linux-ibm<5.15.0-1076.79
5.15.0-1076.79
ubuntu/linux-ibm-6.8<6.8.0-1026.26~22.04.1
6.8.0-1026.26~22.04.1
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1079.85
5.15.0-1079.85
ubuntu/linux-kvm<5.15.0-1080.85
5.15.0-1080.85
ubuntu/linux-lowlatency<5.15.0-140.150
5.15.0-140.150
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8<6.8.0-60.63.1~22.04.1
6.8.0-60.63.1~22.04.1
ubuntu/linux-nvidia<5.15.0-1078.79
5.15.0-1078.79
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1028.31~22.04.1
6.8.0-1028.31~22.04.1
ubuntu/linux-nvidia-tegra<5.15.0-1037.37
5.15.0-1037.37
ubuntu/linux-nvidia-tegra-igx<5.15.0-1026.26
5.15.0-1026.26
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1081.87
5.15.0-1081.87
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8<6.8.0-1026.27~22.04.1
6.8.0-1026.27~22.04.1
ubuntu/linux-raspi<5.15.0-1078.81
5.15.0-1078.81
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-62.65~22.04.1
6.8.0-62.65~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp<5.15.0-1050.54
5.15.0-1050.54
ubuntu/linux-bluefield<5.15.0-1066.68
5.15.0-1066.68
ubuntu/linux-intel-iot-realtime<5.15.0-1077.79
5.15.0-1077.79
ubuntu/linux-realtime<5.15.0-1084.93
5.15.0-1084.93
ubuntu/linux-realtime-6.8<6.8.1-1022.23~22.04.1
6.8.1-1022.23~22.04.1
ubuntu/linux-aws-fips<5.15.0-1084.91+fips1
5.15.0-1084.91+fips1
ubuntu/linux-azure-fips<5.15.0-1089.98+fips1
5.15.0-1089.98+fips1
ubuntu/linux-fips<5.15.0-140.150+fips1
5.15.0-140.150+fips1
ubuntu/linux-gcp-fips<5.15.0-1083.92+fips1
5.15.0-1083.92+fips1
ubuntu/linux<6.8.0-60.63
6.8.0-60.63
ubuntu/linux-aws<6.8.0-1029.31
6.8.0-1029.31
ubuntu/linux-azure<6.8.0-1029.34
6.8.0-1029.34
ubuntu/linux-azure-6.11<6.11.0-1012.12~24.04.1
6.11.0-1012.12~24.04.1
ubuntu/linux-azure-nvidia<6.8.0-1016.17
6.8.0-1016.17
ubuntu/linux-gcp<6.8.0-1030.32
6.8.0-1030.32
ubuntu/linux-gcp-6.11<6.11.0-1011.11~24.04.1
6.11.0-1011.11~24.04.1
ubuntu/linux-gke<6.8.0-1025.29
6.8.0-1025.29
ubuntu/linux-gkeop<6.8.0-1012.14
6.8.0-1012.14
ubuntu/linux-hwe-6.11<6.11.0-21.21~24.04.1
6.11.0-21.21~24.04.1
ubuntu/linux-ibm<6.8.0-1026.26
6.8.0-1026.26
ubuntu/linux-lowlatency<6.8.0-60.63.1
6.8.0-60.63.1
ubuntu/linux-nvidia<6.8.0-1028.31
6.8.0-1028.31
ubuntu/linux-nvidia-6.11<6.11.0-1007.7
6.11.0-1007.7
ubuntu/linux-nvidia-lowlatency<6.8.0-1028.31.1
6.8.0-1028.31.1
ubuntu/linux-nvidia-tegra<6.8.0-1008.8
6.8.0-1008.8
ubuntu/linux-oem-6.11<6.11.0-1017.17
6.11.0-1017.17
ubuntu/linux-oem-6.8<6.8.0-1028.28
6.8.0-1028.28
ubuntu/linux-oracle<6.8.0-1026.27
6.8.0-1026.27
ubuntu/linux-raspi<6.8.0-1028.32
6.8.0-1028.32
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv<6.8.0-60.63.1
6.8.0-60.63.1
ubuntu/linux-raspi-realtime<6.8.0-2023.24
6.8.0-2023.24
ubuntu/linux-realtime<6.8.1-1022.23
6.8.1-1022.23
ubuntu/linux-vmware*
debian/linux
6.1.176-16.1.190-16.12.107-16.12.116-17.2.15-17.3.4-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

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

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.3-1
  2. Upgrade

    Upgrade ubuntu/linux-aws-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1146.156~18.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1151.158~18.04.1
  4. Upgrade

    Upgrade ubuntu/linux-gcp-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1149.158~18.04.1
  5. Upgrade

    Upgrade ubuntu/linux-hwe-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-216.236~18.04.1
  6. Upgrade

    Upgrade ubuntu/linux-ibm-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1092.97~18.04.1
  7. Upgrade

    Upgrade ubuntu/linux-oracle-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1144.154~18.04.1
  8. Upgrade

    Upgrade ubuntu/linux-raspi-5.4 to a version that resolves this vulnerability.

    Fixed in 5.4.0-1129.142~18.04.1
  9. Upgrade

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

    Fixed in 5.4.0-216.236
  10. Upgrade

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

    Fixed in 5.4.0-1146.156
  11. Upgrade

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

    Fixed in 5.15.0-1084.91~20.04.1
  12. Upgrade

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

    Fixed in 5.4.0-1151.158
  13. Upgrade

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

    Fixed in 5.15.0-1089.98~20.04.1
  14. Upgrade

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

    Fixed in 5.4.0-1105.112
  15. Upgrade

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

    Fixed in 5.4.0-1149.158
  16. Upgrade

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

    Fixed in 5.15.0-1083.92~20.04.1
  17. Upgrade

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

    Fixed in 5.4.0-1092.97
  18. Upgrade

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

    Fixed in 5.15.0-1076.79~20.04.1
  19. Upgrade

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

    Fixed in 5.15.0-1079.85~20.04.1
  20. Upgrade

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

    Fixed in 5.4.0-1133.142
  21. Upgrade

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

    Fixed in 5.15.0-140.150~20.04.1
  22. Upgrade

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

    Fixed in 5.4.0-1144.154
  23. Upgrade

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

    Fixed in 5.15.0-1081.87~20.04.1
  24. Upgrade

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

    Fixed in 5.4.0-1129.142
  25. Upgrade

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

    Fixed in 5.15.0-1079.83~20.04.1
  26. Upgrade

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

    Fixed in 5.4.0-1064.68
  27. Upgrade

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

    Fixed in 5.15.0-142.152~20.04.1
  28. Upgrade

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

    Fixed in 5.4.0-1051.54
  29. Upgrade

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

    Fixed in 5.15.0-1039.39~20.04.1
  30. Upgrade

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

    Fixed in 5.4.0-1146.156+fips1
  31. Upgrade

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

    Fixed in 5.4.0-1151.158+fips1
  32. Upgrade

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

    Fixed in 5.4.0-1120.130
  33. Upgrade

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

    Fixed in 5.4.0-1149.158+fips1
  34. Upgrade

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

    Fixed in 5.15.0-140.150
  35. Upgrade

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

    Fixed in 5.15.0-1084.91
  36. Upgrade

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

    Fixed in 6.8.0-1029.31~22.04.1
  37. Upgrade

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

    Fixed in 5.15.0-1089.98
  38. Upgrade

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

    Fixed in 6.8.0-1029.34~22.04.1
  39. Upgrade

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

    Fixed in 5.15.0-1089.98.1
  40. Upgrade

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

    Fixed in 5.15.0-1083.92
  41. Upgrade

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

    Fixed in 6.8.0-1030.32~22.04.1
  42. Upgrade

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

    Fixed in 5.15.0-1081.87
  43. Upgrade

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

    Fixed in 5.15.0-1066.74
  44. Upgrade

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

    Fixed in 6.8.0-60.63~22.04.1
  45. Upgrade

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

    Fixed in 5.15.0-1076.79
  46. Upgrade

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

    Fixed in 6.8.0-1026.26~22.04.1
  47. Upgrade

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

    Fixed in 5.15.0-1079.85
  48. Upgrade

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

    Fixed in 5.15.0-1080.85
  49. Upgrade

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

    Fixed in 5.15.0-140.150
  50. Upgrade

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

    Fixed in 6.8.0-60.63.1~22.04.1
  51. Upgrade

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

    Fixed in 5.15.0-1078.79
  52. Upgrade

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

    Fixed in 6.8.0-1028.31~22.04.1
  53. Upgrade

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

    Fixed in 5.15.0-1037.37
  54. Upgrade

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

    Fixed in 5.15.0-1026.26
  55. Upgrade

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

    Fixed in 5.15.0-1081.87
  56. Upgrade

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

    Fixed in 6.8.0-1026.27~22.04.1
  57. Upgrade

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

    Fixed in 5.15.0-1078.81
  58. Upgrade

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

    Fixed in 6.8.0-62.65~22.04.1
  59. Upgrade

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

    Fixed in 5.15.0-1050.54
  60. Upgrade

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

    Fixed in 5.15.0-1066.68
  61. Upgrade

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

    Fixed in 5.15.0-1077.79
  62. Upgrade

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

    Fixed in 5.15.0-1084.93
  63. Upgrade

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

    Fixed in 6.8.1-1022.23~22.04.1
  64. Upgrade

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

    Fixed in 5.15.0-1084.91+fips1
  65. Upgrade

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

    Fixed in 5.15.0-1089.98+fips1
  66. Upgrade

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

    Fixed in 5.15.0-140.150+fips1
  67. Upgrade

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

    Fixed in 5.15.0-1083.92+fips1
  68. Upgrade

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

    Fixed in 6.8.0-60.63
  69. Upgrade

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

    Fixed in 6.8.0-1029.31
  70. Upgrade

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

    Fixed in 6.8.0-1029.34
  71. Upgrade

    Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1012.12~24.04.1
  72. Upgrade

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

    Fixed in 6.8.0-1016.17
  73. Upgrade

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

    Fixed in 6.8.0-1030.32
  74. Upgrade

    Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1011.11~24.04.1
  75. Upgrade

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

    Fixed in 6.8.0-1025.29
  76. Upgrade

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

    Fixed in 6.8.0-1012.14
  77. Upgrade

    Upgrade ubuntu/linux-hwe-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-21.21~24.04.1
  78. Upgrade

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

    Fixed in 6.8.0-1026.26
  79. Upgrade

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

    Fixed in 6.8.0-60.63.1
  80. Upgrade

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

    Fixed in 6.8.0-1028.31
  81. Upgrade

    Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1007.7
  82. Upgrade

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

    Fixed in 6.8.0-1028.31.1
  83. Upgrade

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

    Fixed in 6.8.0-1008.8
  84. Upgrade

    Upgrade ubuntu/linux-oem-6.11 to a version that resolves this vulnerability.

    Fixed in 6.11.0-1017.17
  85. Upgrade

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

    Fixed in 6.8.0-1028.28
  86. Upgrade

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

    Fixed in 6.8.0-1026.27
  87. Upgrade

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

    Fixed in 6.8.0-1028.32
  88. Upgrade

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

    Fixed in 6.8.0-60.63.1
  89. Upgrade

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

    Fixed in 6.8.0-2023.24
  90. Upgrade

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

    Fixed in 6.8.1-1022.23

Event History

Jan 19, 2025
CVE Published
via MITRE·10:18 AM
Data Sourced
via MITRE·10:18 AM
DescriptionSeverity
Data Sourced
via Red Hat·11:02 AM
DescriptionSeverityAffected Software
Data Sourced
via OSV·11:15 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·11:15 AM
Description
Jul 8, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software
Jul 30, 2026
Data Sourced
via NVD·06:17 AM
RemedySeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2025-21647?

CVE-2025-21647 has been classified as a medium severity vulnerability due to its potential impact on performance and stability in the Linux kernel.

2

How do I fix CVE-2025-21647?

To fix CVE-2025-21647, users should update to the latest version of the Linux kernel where the vulnerability has been resolved.

3

What components are affected by CVE-2025-21647?

CVE-2025-21647 affects the scheduling component of the Linux kernel, particularly the sch_cake module.

4

Can CVE-2025-21647 lead to a denial of service?

Yes, CVE-2025-21647 could potentially lead to a denial of service if the vulnerability is exploited to disrupt the host's flow management.

5

Is CVE-2025-21647 considered a logic error?

Yes, CVE-2025-21647 originated from a logic error related to bounds checks in the host's bulk flow fairness counts.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203