U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

CVE-2025-39945 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: cnic: Fix use-after-free bugs in cnic_delete_task The original code uses cancel_delayed_work() in cnic_cm_stop_bnx2x_hw(), which does not guarantee that the delayed work item 'delete_task' has fully completed if it was already running. Additionally, the delayed work item is cyclic, the flush_workqueue() in cnic_cm_stop_bnx2x_hw() only blocks and waits for work items that were already queued to the workqueue prior to its invocation. Any work items submitted after flush_workqueue() is called are not included in the set of tasks that the flush operation awaits. This means that after the cyclic work items have finished executing, a delayed work item may still exist in the workqueue. This leads to use-after-free scenarios where the cnic_dev is deallocated by cnic_free_dev(), while delete_task remains active and attempt to dereference cnic_dev in cnic_delete_task(). A typical race condition is illustrated below: CPU 0 (cleanup) | CPU 1 (delayed work callback) cnic_netdev_event() | cnic_stop_hw() | cnic_delete_task() cnic_cm_stop_bnx2x_hw() | ... cancel_delayed_work() | /* the queue_delayed_work() flush_workqueue() | executes after flush_workqueue()*/ | queue_delayed_work() cnic_free_dev(dev)//free | cnic_delete_task() //new instance | dev = cp->dev; //use Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the cyclic delayed work item is properly canceled and that any ongoing execution of the work item completes before the cnic_dev is deallocated. Furthermore, since cancel_delayed_work_sync() uses __flush_work(work, true) to synchronously wait for any currently executing instance of the work item to finish, the flush_workqueue() becomes redundant and should be removed. This bug was identified through static analysis. To reproduce the issue and validate the fix, I simulated the cnic PCI device in QEMU and introduced intentional delays — such as inserting calls to ssleep() within the cnic_delete_task() function — to increase the likelihood of triggering the bug.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
https://git.kernel.org/stable/c/0405055930264ea8fd26f4131466fa7652e5e47d kernel.org
https://git.kernel.org/stable/c/0627e1481676669cae2df0d85b5ff13e7d24c390 kernel.org
https://git.kernel.org/stable/c/6e33a7eed587062ca8161ad1f4584882a860d697 kernel.org
https://git.kernel.org/stable/c/7b6a5b0a6b392263c3767fc945b311ea04b34bbd kernel.org
https://git.kernel.org/stable/c/8eeb2091e72d75df8ceaa2172638d61b4cf8929a kernel.org
https://git.kernel.org/stable/c/cfa7d9b1e3a8604afc84e9e51d789c29574fb216 kernel.org
https://git.kernel.org/stable/c/e1fcd4a9c09feac0902a65615e866dbf22616125 kernel.org
https://git.kernel.org/stable/c/fde6e73189f40ebcf0633aed2b68e731c25f3aa3 kernel.org

Weakness Enumeration

CWE-ID CWE Name Source

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-39945
NVD Published Date:
10/04/2025
NVD Last Modified:
10/04/2025
Source:
kernel.org