CVSS 7.8 · High EPSS 0,16%
Kerentanan Use After Free pada linux kernel. Skor CVSS 3.1 7.8 (High) menurut NVD.
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 2.6.37 hingga sebelum 5.4.300 |
| linux | linux kernel | Versi 5.5 hingga sebelum 5.10.245 |
| linux | linux kernel | Versi 5.11 hingga sebelum 5.15.194 |
| linux | linux kernel | Versi 5.16 hingga sebelum 6.1.154 |
| linux | linux kernel | Versi 6.2 hingga sebelum 6.6.108 |
| linux | linux kernel | Versi 6.7 hingga sebelum 6.12.49 |
| linux | linux kernel | Versi 6.13 hingga sebelum 6.16.9 |
| linux | linux kernel | Versi 6.17 rc1 |
| linux | linux kernel | Versi 6.17 rc2 |
| linux | linux kernel | Versi 6.17 rc3 |
| linux | linux kernel | Versi 6.17 rc4 |
| linux | linux kernel | Versi 6.17 rc5 |
| linux | linux kernel | Versi 6.17 rc6 |