CVE-2025-40245: nios2: ensure that memblock.current_limit is set when setting pfn limits
In the Linux kernel, the following vulnerability has been resolved:
nios2: ensure that memblock.currentlimit is set when setting pfn limits
On nios2, with CONFIGFLATMEM set, the kernel relies on memblockgetcurrentlimit() to determine the limits of memmap, in particular for maxlowpfn. Unfortunately, memblock.currentlimit is only default initialized to MEMBLOCKALLOCANYWHERE at this point of the bootup, potentially leading to situations where maxlowpfn can erroneously exceed the value of maxpfn and, thus, the valid range of available DRAM.
This can in turn cause kernel-level paging failures, e.g.:
[ 76.900000] Unable to handle kernel paging request at virtual address 20303000 [ 76.900000] ea = c0080890, ra = c000462c, cause = 14 [ 76.900000] Kernel panic - not syncing: Oops [ 76.900000] ---[ end Kernel panic - not syncing: Oops ]---
This patch fixes this by pre-calculating memblock.currentlimit based on the upper limits of the available memory ranges via adjustlowmembounds, a simplified version of the equivalent implementation within the arm architecture.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1100.107~20.04.2 - Upgrade
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ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1110.119~20.04.1 - Upgrade
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ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1100.109~20.04.1 - Upgrade
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ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-170.180~20.04.3 - Upgrade
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ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1094.97~20.04.1 - Upgrade
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ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1095.101~20.04.1 - Upgrade
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ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-170.180~20.04.1 - Upgrade
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ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1052.52~20.04.2 - Upgrade
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ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1097.103~20.04.1 - Upgrade
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ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1095.99~20.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-170.180 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1100.107 - Upgrade
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ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1050.53~22.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1109.118 - Upgrade
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ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1051.57~22.04.1 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1109.118.1 - Upgrade
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ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1058.65~22.04.1 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1100.109 - Upgrade
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ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1052.55~22.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1096.102 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1083.91 - Upgrade
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ubuntu/linux-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-106.106~22.04.1 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1094.97 - Upgrade
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ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1049.49~22.04.1 - Upgrade
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ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1095.101 - Upgrade
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ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1092.97 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-170.180 - Upgrade
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ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-106.106.1~22.04.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1095.96 - Upgrade
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ubuntu/linux-nvidia-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1049.52~22.04.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1052.52 - Upgrade
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ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1041.41 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1097.103 - Upgrade
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ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1047.48~22.04.1 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 5.15.0-1097.100 - Upgrade
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ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-106.106~22.04.1 - Upgrade
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ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.15.0-1064.68 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1084.86 - Upgrade
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ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1092.94 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1099.108 - Upgrade
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ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1045.46~22.04.1 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1100.107+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1109.118+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-170.180+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1100.109+fips1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-106.106 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1050.53 - Upgrade
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ubuntu/linux-aws-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1007.7~24.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1051.57 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1058.65 - Upgrade
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ubuntu/linux-azure-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1039.42 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1052.55 - Upgrade
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ubuntu/linux-gcp-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1008.8~24.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1048.53 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1035.38 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1049.49 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-106.106.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1049.52 - Upgrade
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ubuntu/linux-nvidia-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1008.8 - Upgrade
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ubuntu/linux-nvidia-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-1049.52.1 - Upgrade
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ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1020.20 - Upgrade
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ubuntu/linux-oem-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1011.11 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1047.48 - Upgrade
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ubuntu/linux-oracle-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1007.7~24.04.1 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1050.54 - Upgrade
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ubuntu/linux-xilinxto a version that resolves this vulnerability.Fixed in 6.8.0-1028.29 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1017.21 - Upgrade
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ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2040.41 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1045.46 - Upgrade
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ubuntu/linux-realtime-6.17to a version that resolves this vulnerability.Fixed in 6.17.0-1006.7~24.04.1 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1050.53+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1052.58+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-106.106+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1052.55+fips1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.17.0-14.14 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.17.0-1007.7 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.17.0-1008.8 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.17.0-1007.7 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.17.0-1007.7 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.17.0-1008.8 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.17.0-1006.7 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 6.17.0-14.14.1
Event History
Frequently Asked Questions
What is the severity of CVE-2025-40245?
CVE-2025-40245 has been classified as a moderate severity vulnerability within the Linux kernel.
How do I fix CVE-2025-40245?
To address CVE-2025-40245, ensure you update your Linux kernel to the latest patched version provided by your distribution.
What systems are affected by CVE-2025-40245?
CVE-2025-40245 affects systems running the Linux kernel with CONFIG_FLATMEM enabled on nios2 architectures.
What type of vulnerability is CVE-2025-40245?
CVE-2025-40245 is a local privilege escalation vulnerability in the Linux kernel.
What is the impact of CVE-2025-40245?
The impact of CVE-2025-40245 could allow an attacker to disrupt memory management on affected systems, leading to system instability.