CVE-2025-39859
BaseFortify
Publication date: 2025-09-19
Last updated on: 2025-12-12
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 | From 5.15 (inc) to 6.16.6 (exc) |
| linux | linux_kernel | 6.17 |
| linux | linux_kernel | 6.17 |
| linux | linux_kernel | 6.17 |
| linux | linux_kernel | 6.17 |
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 ptp_ocp watchdog timer. The issue occurs because the ptp_ocp_detach() function only shuts down the watchdog timer if it is pending, but if the timer handler is already running, the timer_delete_sync() function is not called. This creates a race condition where the devlink containing the ptp_ocp is deallocated while the timer handler is still accessing it, leading to use-after-free errors. The fix involves always calling timer_delete_sync() to ensure the timer is properly deactivated and prevent access after the object is freed.
How can this vulnerability impact me? :
This vulnerability can lead to use-after-free conditions, which may cause system instability, crashes, or potentially allow an attacker to execute arbitrary code or escalate privileges by exploiting the race condition in the kernel's timer handling.
What immediate steps should I take to mitigate this vulnerability?
Apply the patch or update to the fixed Linux kernel version that unconditionally calls timer_delete_sync() in the ptp_ocp_detach() function to prevent use-after-free bugs caused by the ptp_ocp_watchdog timer. This ensures the timer is reliably deactivated and race conditions are avoided.