Security assessments indicate that CVE-2021-47271 presents a notable risk, potentially requiring prompt mitigation.
Status: Analyzed
Last updated: 🕑 04 Apr 2025, 14:29 UTC
Originally published on: 🕒 21 May 2024, 15:15 UTC
Time between publication and last update: 317 days
CVSS Release: version 3
134c704f-9b21-4f2e-91b3-4a467353bcc0
Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVE-2021-47271: In the Linux kernel, the following vulnerability has been resolved: usb: cdnsp: Fix deadlock issue in cdnsp_thread_irq_handler Patch fixes the following critical issue caused by deadlock which has been detected during testing NCM class: smp: csd: Detected non-responsive CSD lock (#1) on CPU#0 smp: csd: CSD lock (#1) unresponsive. .... RIP: 0010:native_queued_spin_lock_slowpath+0x61/0x1d0 RSP: 0018:ffffbc494011cde0 EFLAGS: 00000002 RAX: 0000000000000101 RBX: ffff9ee8116b4a68 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ee8116b4658 RBP: ffffbc494011cde0 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658 R13: ffff9ee8116b4670 R14: 0000000000000246 R15: ffff9ee8116b4658 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7bcc41a830 CR3: 000000007a612003 CR4: 00000000001706e0 Call Trace: <IRQ> do_raw_spin_lock+0xc0/0xd0 _raw_spin_lock_irqsave+0x95/0xa0 cdnsp_gadget_ep_queue.cold+0x88/0x107 [cdnsp_udc_pci] usb_ep_queue+0x35/0x110 eth_start_xmit+0x220/0x3d0 [u_ether] ncm_tx_timeout+0x34/0x40 [usb_f_ncm] ? ncm_free_inst+0x50/0x50 [usb_f_ncm] __hrtimer_run_queues+0xac/0x440 hrtimer_run_softirq+0x8c/0xb0 __do_softirq+0xcf/0x428 asm_call_irq_on_stack+0x12/0x20 </IRQ> do_softirq_own_stack+0x61/0x70 irq_exit_rcu+0xc1/0xd0 sysvec_apic_timer_interrupt+0x52/0xb0 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:do_raw_spin_trylock+0x18/0x40 RSP: 0018:ffffbc494138bda8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff9ee8116b4658 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9ee8116b4658 RBP: ffffbc494138bda8 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658 R13: ffff9ee8116b4670 R14: ffff9ee7b5c73d80 R15: ffff9ee8116b4000 _raw_spin_lock+0x3d/0x70 ? cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci] cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci] ? cdnsp_remove_request+0x1f0/0x1f0 [cdnsp_udc_pci] ? cdnsp_thread_irq_handler+0x5/0xa0 [cdnsp_udc_pci] ? irq_thread+0xa0/0x1c0 irq_thread_fn+0x28/0x60 irq_thread+0x105/0x1c0 ? __kthread_parkme+0x42/0x90 ? irq_forced_thread_fn+0x90/0x90 ? wake_threads_waitq+0x30/0x30 ? irq_thread_check_affinity+0xe0/0xe0 kthread+0x12a/0x160 ? kthread_park+0x90/0x90 ret_from_fork+0x22/0x30 The root cause of issue is spin_lock/spin_unlock instruction instead spin_lock_irqsave/spin_lock_irqrestore in cdnsp_thread_irq_handler function.
The exploitability of CVE-2021-47271 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2021-47271 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2021-47271, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2021-47271, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.043% (probability of exploit)
EPSS Percentile: 12.0%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 88.0% of others.
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