CVE-2023-53850: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53850 is a resource leak vulnerability in the Linux kernel's iavf (Intel Adaptive Virtual Function) network driver. The flaw occurs when the system attempts to close a network device (netdev) while iavf_reset_task() is concurrently running, causing iavf_free_traffic_irqs() to be skipped and resulting in an IRQ/proc entry leak. Affected Linux kernel versions span from 4.15 up to the fixes introduced in 6.1.42 and 6.4.7 (with 6.5 also patched). The vulnerability was published on December 9, 2025, and carries an estimated CVSS severity of Medium with an EPSS score of approximately 0.017% (Feedly, EUVD).

The root cause is a race condition (CWE-362) in the iavf driver's interrupt management logic. When iavf_reset_task() runs concurrently with a netdev close operation, the __LINK_STATE_START flag is cleared, causing netif_running() to return false inside iavf_reinit_interrupt_scheme(). As a result, iavf_free_traffic_irqs() is never called, leaking IRQ entries in /proc/irq/ (e.g., iavf-enp24s0f0v0-TxRx-0). The fix replaces the netif_running() check with an internal adapter state check (state == __IAVF_RUNNING), ensuring traffic IRQs are always freed when the adapter is in the running state (Feedly). Patches are available in the stable kernel tree at commits 6d9d016, 5e9db32, and a77ed5c (kernel.org).

Exploitation of this vulnerability results in a resource leak — specifically, IRQ entries and /proc/irq/ directory entries are not freed when the iavf network interface is closed during a reset. This can trigger kernel warnings (WARNING: CPU: 0 PID: 10 at fs/proc/generic.c:718 remove_proc_entry+0x19b/0x1b0) and may cause system instability or denial of service over time as resources accumulate. The impact is limited to availability (system stability) on hosts using Intel SR-IOV virtual function network adapters; there is no known confidentiality or integrity impact (Feedly).

The fix is included in Linux kernel stable releases 6.1.42, 6.4.7, and 6.5. Users should update to a patched kernel version that includes commits 6d9d01689b82ff5cb8f8d2a82717d7997bc0bfff, 5e9db32eec628481f5da97a5b1aedb84a5240d18, or a77ed5c5b768e9649be240a2d864e5cd9c6a2015 as appropriate for their kernel branch (kernel.org). SUSE has also issued advisories (SUSE-2026-0281-1 and SUSE-2026-20876-1) addressing this CVE in their kernel packages (Linux Security). As a temporary workaround, avoiding concurrent netdev close operations during iavf resets may reduce the likelihood of triggering the race condition, though upgrading is strongly preferred.