{"cve":"CVE-2021-47271","nvd":{"published":"2024-05-21T15:15:15.610","modified":"2026-06-17T04:17:04.120","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: cdnsp: Fix deadlock issue in cdnsp_thread_irq_handler\n\nPatch fixes the following critical issue caused by deadlock which has been\ndetected during testing NCM class:\n\nsmp: csd: Detected non-responsive CSD lock (#1) on CPU#0\nsmp:     csd: CSD lock (#1) unresponsive.\n....\nRIP: 0010:native_queued_spin_lock_slowpath+0x61/0x1d0\nRSP: 0018:ffffbc494011cde0 EFLAGS: 00000002\nRAX: 0000000000000101 RBX: ffff9ee8116b4a68 RCX: 0000000000000000\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ee8116b4658\nRBP: ffffbc494011cde0 R08: 0000000000000001 R09: 0000000000000000\nR10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658\nR13: ffff9ee8116b4670 R14: 0000000000000246 R15: ffff9ee8116b4658\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f7bcc41a830 CR3: 000000007a612003 CR4: 00000000001706e0\nCall Trace:\n <IRQ>\n do_raw_spin_lock+0xc0/0xd0\n _raw_spin_lock_irqsave+0x95/0xa0\n cdnsp_gadget_ep_queue.cold+0x88/0x107 [cdnsp_udc_pci]\n usb_ep_queue+0x35/0x110\n eth_start_xmit+0x220/0x3d0 [u_ether]\n ncm_tx_timeout+0x34/0x40 [usb_f_ncm]\n ? ncm_free_inst+0x50/0x50 [usb_f_ncm]\n __hrtimer_run_queues+0xac/0x440\n hrtimer_run_softirq+0x8c/0xb0\n __do_softirq+0xcf/0x428\n asm_call_irq_on_stack+0x12/0x20\n </IRQ>\n do_softirq_own_stack+0x61/0x70\n irq_exit_rcu+0xc1/0xd0\n sysvec_apic_timer_interrupt+0x52/0xb0\n asm_sysvec_apic_timer_interrupt+0x12/0x20\nRIP: 0010:do_raw_spin_trylock+0x18/0x40\nRSP: 0018:ffffbc494138bda8 EFLAGS: 00000246\nRAX: 0000000000000000 RBX: ffff9ee8116b4658 RCX: 0000000000000000\nRDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9ee8116b4658\nRBP: ffffbc494138bda8 R08: 0000000000000001 R09: 0000000000000000\nR10: ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658\nR13: ffff9ee8116b4670 R14: ffff9ee7b5c73d80 R15: ffff9ee8116b4000\n _raw_spin_lock+0x3d/0x70\n ? cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci]\n cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci]\n ? cdnsp_remove_request+0x1f0/0x1f0 [cdnsp_udc_pci]\n ? cdnsp_thread_irq_handler+0x5/0xa0 [cdnsp_udc_pci]\n ? irq_thread+0xa0/0x1c0\n irq_thread_fn+0x28/0x60\n irq_thread+0x105/0x1c0\n ? __kthread_parkme+0x42/0x90\n ? irq_forced_thread_fn+0x90/0x90\n ? wake_threads_waitq+0x30/0x30\n ? irq_thread_check_affinity+0xe0/0xe0\n kthread+0x12a/0x160\n ? kthread_park+0x90/0x90\n ret_from_fork+0x22/0x30\n\nThe root cause of issue is spin_lock/spin_unlock instruction instead\nspin_lock_irqsave/spin_lock_irqrestore in cdnsp_thread_irq_handler\nfunction.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-667"],"references":["https://git.kernel.org/stable/c/a9aecef198faae3240921b707bc09b602e966fce","https://git.kernel.org/stable/c/ae746b6f4ce619cf4032fd798a232b010907a397","https://git.kernel.org/stable/c/a9aecef198faae3240921b707bc09b602e966fce","https://git.kernel.org/stable/c/ae746b6f4ce619cf4032fd798a232b010907a397"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47271","score":0.00147,"percentile":0.03879,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}