cbcvebase.
CVE-2025-39945
published 2025-10-04

CVE-2025-39945: In the Linux kernel, the following vulnerability has been resolved: cnic: Fix use-after-free bugs in cnic_delete_task The original code uses…

PriorityP341high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.15%
4.4th percentile
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() wit

Affected

31 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.158-1 (bookworm)linux 6.1.158-1 (bookworm)
debianlinux-6.1< linux 6.1.158-1 (bookworm)linux 6.1.158-1 (bookworm)
linuxlinux
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < fde6e73189f40ebcf0633aed2b68e731c25f3aa3fde6e73189f40ebcf0633aed2b68e731c25f3aa3
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < 7b6a5b0a6b392263c3767fc945b311ea04b34bbd7b6a5b0a6b392263c3767fc945b311ea04b34bbd
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < 0405055930264ea8fd26f4131466fa7652e5e47d0405055930264ea8fd26f4131466fa7652e5e47d
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < e1fcd4a9c09feac0902a65615e866dbf22616125e1fcd4a9c09feac0902a65615e866dbf22616125
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < 8eeb2091e72d75df8ceaa2172638d61b4cf8929a8eeb2091e72d75df8ceaa2172638d61b4cf8929a
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < 6e33a7eed587062ca8161ad1f4584882a860d6976e33a7eed587062ca8161ad1f4584882a860d697
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < 0627e1481676669cae2df0d85b5ff13e7d24c3900627e1481676669cae2df0d85b5ff13e7d24c390
linuxlinux>= fdf24086f4752aee5dfb40143c736250df017820 < cfa7d9b1e3a8604afc84e9e51d789c29574fb216cfa7d9b1e3a8604afc84e9e51d789c29574fb216
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.247-15.10.247-1
linuxlinux_kernel>= 0 < 6.1.158-16.1.158-1
linuxlinux_kernel>= 0 < 6.12.57-16.12.57-1
linuxlinux_kernel>= 0 < 6.16.9-16.16.9-1
linuxlinux_kernel>= 0 < 5.15.0-170.1805.15.0-170.180
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 2.6.37 < 5.4.3005.4.300
linuxlinux_kernel>= 5.11 < 5.15.1945.15.194
linuxlinux_kernel>= 5.16 < 6.1.1546.1.154
linuxlinux_kernel>= 5.5 < 5.10.2455.10.245
linuxlinux_kernel>= 6.13 < 6.16.96.16.9
linuxlinux_kernel>= 6.2 < 6.6.1086.6.108
linuxlinux_kernel>= 6.7 < 6.12.496.12.49

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_msrc7.8HIGH
vendor_redhat7.8HIGH
vendor_ubuntu7.8HIGH
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