CVE-2023-54288 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fortify the spinlock against deadlock by interrupt
In the function ieee80211_tx_dequeue() there is a particular locking sequence:
begin: spin_lock(&local->queue_stop_reason_lock); q_stopped = local->queue_stop_reasons[q];
spin_unlock(&local->queue_stop_reason_lock);
However small the chance (increased by ftracetest), an asynchronous interrupt can occur in between of spin_lock() and spin_unlock(), and the interrupt routine will attempt to lock the same &local->queue_stop_reason_lock again.
This will cause a costly reset of the CPU and the wifi device or an altogether hang in the single CPU and single core scenario.
The only remaining spin_lock(&local->queue_stop_reason_lock) that did not disable interrupts was patched, which should prevent any deadlocks on the same CPU/core and the same wifi device.
This is the probable trace of the deadlock:
kernel: ================================ kernel: WARNING: inconsistent lock state kernel: 6.3.0-rc6-mt-20230401-00001-gf86822a1170f #4 Tainted: G W kernel: -------------------------------- kernel: inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kernel: kworker/5:0/25656 [HC0[0]:SC0[0]:HE1:SE1] takes:
kernel: ffff9d6190779478 (&local->queue_stop_reason_lock){+.?.}-{2:2}, at: return_to_handler+0x0/0x40
kernel: {IN-SOFTIRQ-W} state was registered at:
kernel: lock_acquire+0xc7/0x2d0 kernel: _raw_spin_lock+0x36/0x50 kernel: ieee80211_tx_dequeue+0xb4/0x1330 [mac80211]
kernel: iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm]
kernel: iwl_mvm_mac_wake_tx_queue+0x2d/0xd0 [iwlmvm]
kernel: ieee80211_queue_skb+0x450/0x730 [mac80211]
kernel: __ieee80211_xmit_fast.constprop.66+0x834/0xa50 [mac80211]
kernel: __ieee80211_subif_start_xmit+0x217/0x530 [mac80211]
kernel: ieee80211_subif_start_xmit+0x60/0x580 [mac80211]
kernel: dev_hard_start_xmit+0xb5/0x260 kernel: __dev_queue_xmit+0xdbe/0x1200 kernel: neigh_resolve_output+0x166/0x260 kernel: ip_finish_output2+0x216/0xb80 kernel: __ip_finish_output+0x2a4/0x4d0 kernel: ip_finish_output+0x2d/0xd0 kernel: ip_output+0x82/0x2b0 kernel: ip_local_out+0xec/0x110 kernel: igmpv3_sendpack+0x5c/0x90 kernel: igmp_ifc_timer_expire+0x26e/0x4e0 kernel: call_timer_fn+0xa5/0x230 kernel: run_timer_softirq+0x27f/0x550 kernel: __do_softirq+0xb4/0x3a4 kernel: irq_exit_rcu+0x9b/0xc0 kernel: sysvec_apic_timer_interrupt+0x80/0xa0 kernel: asm_sysvec_apic_timer_interrupt+0x1f/0x30 kernel: _raw_spin_unlock_irqrestore+0x3f/0x70 kernel: free_to_partial_list+0x3d6/0x590 kernel: __slab_free+0x1b7/0x310 kernel: kmem_cache_free+0x52d/0x550 kernel: putname+0x5d/0x70 kernel: do_sys_openat2+0x1d7/0x310 kernel: do_sys_open+0x51/0x80 kernel: __x64_sys_openat+0x24/0x30 kernel: do_syscall_64+0x5c/0x90 kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc kernel: irq event stamp: 5120729 kernel: hardirqs last enabled at (5120729): [<ffffffff9d149936>] trace_graph_return+0xd6/0x120
kernel: hardirqs last disabled at (5120728): [<ffffffff9d149950>] trace_graph_return+0xf0/0x120
kernel: softirqs last enabled at (5069900): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40
kernel: softirqs last disabled at (5067555): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40
kernel: other info that might help us debug this: kernel: Possible unsafe locking scenario: kernel: CPU0 kernel: ---- kernel: lock(&local->queue_stop_reason_lock); kernel: <Interrupt> kernel: lock(&local->queue_stop_reason_lock); kernel: *** DEADLOCK *** kernel: 8 locks held by kworker/5:0/25656: kernel: #0: ffff9d618009d138 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x1ca/0x530
kernel: #1: ffffb1ef4637fe68 ((work_completion)(&local->restart_work)){+.+.}-{0:0}, at: process_one_work+0x1ce/0x530
kernel: #2: ffffffff9f166548 (rtnl_mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40
kernel: #3: ffff9d619 ---truncated---
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Analysis
by VulDB Data Team • 04/27/2026
The vulnerability identified as CVE-2023-54288 resides within the Linux kernel's mac80211 subsystem, specifically affecting the ieee80211_tx_dequeue function where a potential deadlock scenario can occur due to improper spinlock handling during interrupt contexts. This issue manifests when an asynchronous interrupt occurs between the acquisition and release of a spinlock, creating a condition where the same lock is attempted to be acquired twice by the same CPU core, leading to system instability or complete hang. The vulnerability is classified under CWE-367, which addresses Time-of-Check to Time-of-Use (TOCTOU) flaws, and more specifically relates to improper locking mechanisms that can lead to deadlock conditions in concurrent environments. The root cause stems from a particular locking sequence in the ieee80211_tx_dequeue function where the spinlock is acquired without disabling interrupts, allowing an interrupt handler to execute and attempt to acquire the same lock, creating a circular dependency that results in system-wide blocking.
The operational impact of this vulnerability extends beyond simple system performance degradation to potentially catastrophic system failure, especially in single-core or single-CPU environments where the deadlock condition cannot be resolved through thread migration or parallel execution. The deadlock scenario described in the kernel trace shows that a kworker thread attempting to acquire the queue_stop_reason_lock in interrupt context causes the system to hang, as the lock acquisition fails due to the interrupt handler's attempt to reacquire the same lock. This condition can trigger the kernel's lock validator subsystem, which detects inconsistent lock states and reports warnings about the improper locking behavior. The vulnerability affects wireless networking functionality and can result in complete loss of network connectivity for the affected device, with the system requiring manual intervention or reboot to recover from the deadlock state.
Mitigation strategies for this vulnerability involve ensuring that all spinlock acquisitions within interrupt contexts properly disable interrupts to prevent the race condition that leads to deadlock. The fix implemented addresses the specific locking sequence by modifying the spinlock usage to properly disable interrupts during the critical section, thereby preventing asynchronous interrupt handlers from attempting to acquire the same lock. This approach aligns with ATT&CK framework technique T1490, which addresses system network denial, as the vulnerability can lead to complete network service disruption. Organizations should prioritize applying kernel updates that include this fix, particularly in environments where wireless connectivity is critical and system stability is paramount. Additional defensive measures include monitoring for kernel lock validator warnings and implementing robust system monitoring to detect early signs of lock contention that could precede deadlock conditions. The fix represents a fundamental improvement in concurrent programming practices within the kernel's wireless subsystem, addressing a design flaw that could have been exploited to cause persistent system unavailability.