CVE-2025-38734
BaseFortify
Publication date: 2025-09-05
Last updated on: 2025-11-25
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 6.17 |
| linux | linux_kernel | 6.17 |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 (UAF) issue in the Linux kernel's SMC (Shared Memory Communications) subsystem, specifically in the smc_listen_out() function. It occurs because after smc_listen_out_connected() is called, the new client socket's sk pointer may become NULL if the socket is closed immediately after being accepted. This leads to a situation where the kernel tries to access a freed or NULL pointer, causing a kernel NULL pointer dereference and potential system instability or crashes.
How can this vulnerability impact me? :
This vulnerability can cause kernel crashes or system instability due to the NULL pointer dereference in the Linux kernel. If exploited, it could lead to denial of service by crashing the system or potentially allow an attacker to execute arbitrary code in kernel mode, depending on the context and exploitability.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring kernel logs for specific error messages related to the use-after-free (UAF) issue in the smc_listen_out() function. Look for kernel oops or BUG messages indicating NULL pointer dereferences in smc_listen_work, such as lines containing 'BUG: kernel NULL pointer dereference' or 'Oops: 0000'. You can use the command 'dmesg | grep -i smc_listen_work' or 'journalctl -k | grep -i smc_listen_work' to check for these errors in the kernel logs.
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation is to update the Linux kernel to a version where this vulnerability is fixed. The fix involves correcting the order of operations in smc_listen_out_connected() to prevent the use-after-free condition. Until an update is applied, avoid using the SMC (Shared Memory Communications) feature or disable the smc kernel module if possible to reduce exposure.