Race Condition Affecting libperf package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-CENTOS9-LIBPERF-13396264
- published7 Oct 2025
- disclosed4 Oct 2025
Introduced: 4 Oct 2025
NewCVE-2025-39945 (opens in a new tab)How to fix?
There is no fixed version for Centos:9 libperf.
NVD Description
Note: Versions mentioned in the description apply only to the upstream libperf package and not the libperf package as distributed by Centos.
See How to fix? for Centos:9 relevant fixed versions and status.
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.
References
- https://access.redhat.com/security/cve/CVE-2025-39945
- https://git.kernel.org/stable/c/0405055930264ea8fd26f4131466fa7652e5e47d
- https://git.kernel.org/stable/c/0627e1481676669cae2df0d85b5ff13e7d24c390
- https://git.kernel.org/stable/c/6e33a7eed587062ca8161ad1f4584882a860d697
- https://git.kernel.org/stable/c/7b6a5b0a6b392263c3767fc945b311ea04b34bbd
- https://git.kernel.org/stable/c/8eeb2091e72d75df8ceaa2172638d61b4cf8929a
- https://git.kernel.org/stable/c/cfa7d9b1e3a8604afc84e9e51d789c29574fb216
- https://git.kernel.org/stable/c/e1fcd4a9c09feac0902a65615e866dbf22616125
- https://git.kernel.org/stable/c/fde6e73189f40ebcf0633aed2b68e731c25f3aa3