{"id":"CVE-2025-71132","title":"smc91x: fix broken irq-context in PREEMPT_RT","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmc91x: fix broken irq-context in PREEMPT_RT\n\nWhen smc91x.c is built with PREEMPT_RT, the following splat occurs\nin FVP_RevC:\n\n[   13.055000] smc91x LNRO0003:00 eth0: l…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 1c4cb705e733250d13243f6a69b8b5a92e39b9f6","Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 9d222141b00156509d67d80c771fbefa92c43ace","Linux >= 342a93247e0837101f27bbcca26f402902df98dc < ef277ae121b3249c99994652210a326b52d527b0","Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 36561b86cb2501647662cfaf91286dd6973804a6","Linux >= 342a93247e0837101f27bbcca26f402902df98dc < b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3","Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 6402078bd9d1ed46e79465e1faaa42e3458f8a33","Linux 5.15"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-06-10T20:42:13.928914Z"},"published":"2026-01-14","updated":"2026-10-19","sourceUpdated":"2026-10-19T18:15:15.774Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-71132","references":[{"url":"https://git.kernel.org/stable/c/1c4cb705e733250d13243f6a69b8b5a92e39b9f6"},{"url":"https://git.kernel.org/stable/c/9d222141b00156509d67d80c771fbefa92c43ace"},{"url":"https://git.kernel.org/stable/c/ef277ae121b3249c99994652210a326b52d527b0"},{"url":"https://git.kernel.org/stable/c/36561b86cb2501647662cfaf91286dd6973804a6"},{"url":"https://git.kernel.org/stable/c/b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3"},{"url":"https://git.kernel.org/stable/c/6402078bd9d1ed46e79465e1faaa42e3458f8a33"}],"tags":["cve.org"],"epss":0.00279,"epssPercentile":0.19164,"ingestedAt":"2026-10-19T18:35:50.131Z","slug":"CVE-2025-71132","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmc91x: fix broken irq-context in PREEMPT_RT\n\nWhen smc91x.c is built with PREEMPT_RT, the following splat occurs\nin FVP_RevC:\n\n[   13.055000] smc91x LNRO0003:00 eth0: link up, 10Mbps, half-duplex, lpa 0x0000\n[   13.062137] BUG: workqueue leaked atomic, lock or RCU: kworker/2:1[106]\n[   13.062137]      preempt=0x00000000 lock=0->0 RCU=0->1 workfn=mld_ifc_work\n[   13.062266] C\n** replaying previous printk message **\n[   13.062266] CPU: 2 UID: 0 PID: 106 Comm: kworker/2:1 Not tainted 6.18.0-dirty #179 PREEMPT_{RT,(full)}\n[   13.062353] Hardware name:  , BIOS\n[   13.062382] Workqueue: mld mld_ifc_work\n[   13.062469] Call trace:\n[   13.062494]  show_stack+0x24/0x40 (C)\n[   13.062602]  __dump_stack+0x28/0x48\n[   13.062710]  dump_stack_lvl+0x7c/0xb0\n[   13.062818]  dump_stack+0x18/0x34\n[   13.062926]  process_scheduled_works+0x294/0x450\n[   13.063043]  worker_thread+0x260/0x3d8\n[   13.063124]  kthread+0x1c4/0x228\n[   13.063235]  ret_from_fork+0x10/0x20\n\nThis happens because smc_special_trylock() disables IRQs even on PREEMPT_RT,\nbut smc_special_unlock() does not restore IRQs on PREEMPT_RT.\nThe reason is that smc_special_unlock() calls spin_unlock_irqrestore(),\nand rcu_read_unlock_bh() in __dev_queue_xmit() cannot invoke\nrcu_read_unlock() through __local_bh_enable_ip() when current->softirq_disable_cnt becomes zero.\n\nTo address this issue, replace smc_special_trylock() with spin_trylock_irqsave().\n\n## Affected\n\n- `Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 1c4cb705e733250d13243f6a69b8b5a92e39b9f6`\n- `Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 9d222141b00156509d67d80c771fbefa92c43ace`\n- `Linux >= 342a93247e0837101f27bbcca26f402902df98dc < ef277ae121b3249c99994652210a326b52d527b0`\n- `Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 36561b86cb2501647662cfaf91286dd6973804a6`\n- `Linux >= 342a93247e0837101f27bbcca26f402902df98dc < b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3`\n- `Linux >= 342a93247e0837101f27bbcca26f402902df98dc < 6402078bd9d1ed46e79465e1faaa42e3458f8a33`\n- `Linux 5.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}