UBUNTU-CVE-2025-21639: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: rtomin/max: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using containerof(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use 'data' everywhere 'net->sctp.rtomin/max' is used.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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ubuntu/linux-aws-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-1142.152~18.04.1 - Upgrade
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ubuntu/linux-azure-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-1147.154~18.04.1 - Upgrade
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ubuntu/linux-gcp-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-1145.154~18.04.1 - Upgrade
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ubuntu/linux-hwe-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-211.231~18.04.1 - Upgrade
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ubuntu/linux-ibm-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-1090.95~18.04.1 - Upgrade
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ubuntu/linux-oracle-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-1140.149~18.04.1 - Upgrade
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ubuntu/linux-raspi-5.4to a version that resolves this vulnerability.Fixed in 5.4.0-1129.142~18.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.4.0-211.231 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.4.0-1142.152 - Upgrade
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ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1080.87~20.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.4.0-1147.154 - Upgrade
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ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1086.95~20.04.1 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.4.0-1101.108 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.4.0-1145.154 - Upgrade
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ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1081.90~20.04.1 - Upgrade
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ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-136.147~20.04.1 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.4.0-1088.93 - Upgrade
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ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1074.77~20.04.1 - Upgrade
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ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1077.83~20.04.1 - Upgrade
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ubuntu/linux-iotto a version that resolves this vulnerability.Fixed in 5.4.0-1048.51 - Upgrade
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ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.4.0-1129.138 - Upgrade
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ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-135.146~20.04.1 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.4.0-1140.150 - Upgrade
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ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1077.83~20.04.1 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 5.4.0-1129.142 - Upgrade
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ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1075.79~20.04.1 - Upgrade
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ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.4.0-1060.64 - Upgrade
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ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1039.39~20.04.1 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.4.0-1142.153+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.4.0-1147.154+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.4.0-1116.126 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.4.0-1145.154+fips1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-135.146 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1080.87 - Upgrade
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ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1029.31~22.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1084.93 - Upgrade
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ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1029.34~22.04.1 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1084.93.1 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1079.88 - Upgrade
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ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1030.32~22.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1077.83 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1062.70 - Upgrade
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ubuntu/linux-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-60.63~22.04.1 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1072.75 - Upgrade
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ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1026.26~22.04.1 - Upgrade
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ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1073.75 - Upgrade
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ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1075.81 - Upgrade
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ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1076.81 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-135.146 - Upgrade
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ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-60.63.1~22.04.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1074.75 - Upgrade
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ubuntu/linux-nvidia-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1028.31~22.04.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1033.33 - Upgrade
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ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1021.21 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1077.83 - Upgrade
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ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1026.27~22.04.1 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 5.15.0-1074.77 - Upgrade
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ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-62.65~22.04.1 - Upgrade
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ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.15.0-1044.48 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1062.64 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1080.88 - Upgrade
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ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1022.23~22.04.1 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1080.87+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1083.92+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-135.146+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1079.88+fips1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-60.63 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1029.31 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1029.34 - Upgrade
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ubuntu/linux-azure-6.11to a version that resolves this vulnerability.Fixed in 6.11.0-1012.12~24.04.1 - Upgrade
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ubuntu/linux-azure-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1030.32 - Upgrade
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ubuntu/linux-gcp-6.11to a version that resolves this vulnerability.Fixed in 6.11.0-1011.11~24.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1025.29 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1012.14 - Upgrade
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ubuntu/linux-hwe-6.11to a version that resolves this vulnerability.Fixed in 6.11.0-21.21~24.04.1 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1026.26 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-60.63.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1028.31 - Upgrade
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ubuntu/linux-nvidia-6.11to a version that resolves this vulnerability.Fixed in 6.11.0-1007.7 - Upgrade
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ubuntu/linux-nvidia-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-1028.31.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1008.8 - Upgrade
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ubuntu/linux-oem-6.11to a version that resolves this vulnerability.Fixed in 6.11.0-1017.17 - Upgrade
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ubuntu/linux-oem-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1028.28 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1026.27 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1028.32 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 6.8.0-60.63.1 - Upgrade
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ubuntu/linux-xilinxto a version that resolves this vulnerability.Fixed in 6.8.0-1017.18 - Upgrade
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ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2023.24 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1022.23 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-78.78+fips1
Event History
Frequently Asked Questions
What access does an attacker need to trigger this issue?
The issue is locally exploitable and requires low privileges. No user interaction is required.
What is the impact if the vulnerability is triggered?
The affected kernel can hit a NULL-pointer dereference and Oops, resulting in a denial of service. The provided vector indicates no confidentiality or integrity impact.
Which Ubuntu kernel packages are listed as affected?
The listed software includes ubuntu/linux, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, and their listed FIPS variants: ubuntu/linux-fips, ubuntu/linux-aws-fips, and ubuntu/linux-azure-fips.
Under what condition can the crash occur?
The crash can occur when the code accesses current->nsproxy while the current task is exiting, because nsproxy may be NULL. The report notes this was observed in connection with acct(2).