CVE-2025-38620
BaseFortify
Publication date: 2025-08-22
Last updated on: 2025-11-26
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 6.16 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a use-after-free bug in the Linux kernel's zoned loop (zloop) device driver. When a zloop device is removed, the kernel frees memory for a structure (zlo) but then later accesses that freed memory, causing a KASAN (Kernel Address Sanitizer) use-after-free error. Specifically, the function zloop_ctl_remove() calls put_disk(), which eventually frees the zlo memory, but then calls blk_mq_free_tag_set() on a tag_set inside the freed memory, leading to the bug. The fix moves the call to blk_mq_free_tag_set() before the memory is freed to prevent accessing freed memory.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to access freed memory, leading to kernel crashes or instability. It may also expose the system to potential security risks such as memory corruption or exploitation by attackers to execute arbitrary code or cause denial of service.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, ensure that your Linux kernel is updated to a version where the zloop device fix is applied. The fix involves moving the call to blk_mq_free_tag_set() into zloop_free_disk() to prevent use-after-free errors. Applying the latest kernel patches or updates that include this fix will prevent the KASAN use-after-free BUG.