CVE-2025-68198
BaseFortify
Publication date: 2025-12-16
Last updated on: 2025-12-18
Assigner: kernel.org
Description
Description
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability occurs in the Linux kernel's crashkernel memory reservation system. When crashkernel is configured with a high memory reservation and then shrunk below the low crashkernel reservation, it causes two problems: invalid crashkernel resource objects and a kernel crash if the shrinking is done twice. Specifically, shrinking crashkernel memory incorrectly updates the wrong resource object, leading to inconsistent memory reservation states and potentially causing a kernel NULL pointer dereference crash.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to crash when the crashkernel memory reservation is shrunk multiple times below a certain threshold. This can lead to system instability or downtime, as the kernel may experience a NULL pointer dereference and crash, impacting system reliability and availability.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
You can detect this vulnerability by checking the crashkernel memory reservation on your system. Use the command `cat /proc/iomem | grep -i crash` to view the current crashkernel memory reservations. If the crashkernel memory has been shrunk below the low reservation but the /proc/iomem output still shows the old higher reservation, this indicates the vulnerability. Additionally, shrinking the crashkernel memory twice (e.g., echoing a smaller value to /sys/kernel/kexec_crash_size multiple times) may cause a kernel crash, which is another sign of the issue.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, avoid shrinking the crashkernel memory reservation below the low crashkernel reservation, especially avoid shrinking it multiple times. Ensure that any changes to crashkernel memory reservations are done carefully and preferably update to a Linux kernel version where this issue is fixed, as the vulnerability arises from incorrect updates to crashkernel resource objects during shrinking.