CVE-2025-38544: rxrpc: Fix bug due to prealloc collision
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix bug due to prealloc collision
When userspace is using AFRXRPC to provide a server, it has to preallocate incoming calls and assign to them call IDs that will be used to thread related recvmsg() and sendmsg() together. The preallocated call IDs will automatically be attached to calls as they come in until the pool is empty.
To the kernel, the call IDs are just arbitrary numbers, but userspace can use the call ID to hold a pointer to prepared structs. In any case, the user isn't permitted to create two calls with the same call ID (call IDs become available again when the call ends) and EBADSLT should result from sendmsg() if an attempt is made to preallocate a call with an in-use call ID.
However, the cleanup in the error handling will trigger both assertions in rxrpccleanupcall() because the call isn't marked complete and isn't marked as having been released.
Fix this by setting the call state in rxrpcservicepreallocone() and then marking it as being released before calling the cleanup function.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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Fixed in 6.6.104.2-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.41-1 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.16.3-1 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.1.191 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.6.99 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.12.39 - Upgrade
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linux/Kernelto a version that resolves this vulnerability.Fixed in 6.15.7 - Upgrade
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debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.15-1 - Upgrade
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ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1046.49~22.04.1 - 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-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1046.53~22.04.1 - Upgrade
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ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1047.50~22.04.2 - Upgrade
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ubuntu/linux-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-100.100~22.04.1 - Upgrade
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ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1044.44~22.04.1 - Upgrade
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ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-100.100.1~22.04.1 - Upgrade
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ubuntu/linux-nvidia-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1046.49~22.04.1 - Upgrade
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ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1043.44~22.04.1 - Upgrade
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ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-100.100~22.04.1 - Upgrade
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ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1041.42~22.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-100.100 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1046.49 - Upgrade
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ubuntu/linux-aws-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1046.52 - Upgrade
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ubuntu/linux-azure-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1046.53 - 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 6.8.0-1047.50 - Upgrade
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ubuntu/linux-gcp-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-1020.21~24.04.1 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1043.48 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1030.33 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1044.44 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-100.100.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1046.49 - Upgrade
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ubuntu/linux-nvidia-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-1046.49.1 - 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-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-1016.16 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1043.44 - Upgrade
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ubuntu/linux-oracle-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1047.51 - Upgrade
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ubuntu/linux-riscv-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-36.36.1~24.04.1 - Upgrade
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ubuntu/linux-xilinxto a version that resolves this vulnerability.Fixed in 6.8.0-1023.24 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1016.20 - Upgrade
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ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2037.38 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1041.42 - Upgrade
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ubuntu/linux-realtime-6.14to a version that resolves this vulnerability.Fixed in 6.14.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1046.49+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1046.52+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-100.100+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1047.50+fips1 - Compensating control
In rxrpc_service_prealloc_one(), set the call state and mark the call as released before invoking the cleanup function; ensure that attempting to preallocate a call with an in-use call ID results in EBADSLT from sendmsg().
Event History
Frequently Asked Questions
What is the severity of CVE-2025-38544?
CVE-2025-38544 is classified as a moderate severity vulnerability in the Linux kernel.
How do I fix CVE-2025-38544?
To mitigate CVE-2025-38544, ensure that you are using a patched version of the Linux kernel that addresses this vulnerability.
What does CVE-2025-38544 affect?
CVE-2025-38544 affects the Linux kernel, specifically the AF_RXRPC component used for handling incoming calls.
Can CVE-2025-38544 be exploited?
Yes, CVE-2025-38544 can potentially be exploited by attackers that manipulate the preallocation of incoming calls in affected configurations.
Is CVE-2025-38544 present in all versions of the Linux kernel?
No, CVE-2025-38544 is present in specific versions of the Linux kernel that do not have the vulnerability patched.