{"id":"CVE-2026-80548","title":"s390/vfio_ccw: Selectively expand io_mutex","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Selectively expand io_mutex\n\nThe io_mutex was defined to serialize the io_regions, but then has\nalso sort of been associated with the I/O themselves beca…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < dab6a6627b0b0cce23653e99c7b0bf8c6cfd82e0","Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 56d7488533ceac4e986e96e15c9e487a2245bc01","Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < f72a51810d49411bd8cad0c2df8592320a2fe5cc","Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 2ba9efdf9ebedc4e54df4b56aa3b43a65f7967cd","Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < b6aecea4b2b246f9fbd98a5712daa1193a60818e","Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 2a5ac0c0f1f7da33929211a2e41911bf72ee35d8","Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 34f4feff3e90bd09308fad0974e97113b23b812a","Linux 5.2"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:17:03.411109Z"},"published":"2026-08-26","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:26:25.857Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80548","references":[{"url":"https://git.kernel.org/stable/c/dab6a6627b0b0cce23653e99c7b0bf8c6cfd82e0"},{"url":"https://git.kernel.org/stable/c/56d7488533ceac4e986e96e15c9e487a2245bc01"},{"url":"https://git.kernel.org/stable/c/f72a51810d49411bd8cad0c2df8592320a2fe5cc"},{"url":"https://git.kernel.org/stable/c/2ba9efdf9ebedc4e54df4b56aa3b43a65f7967cd"},{"url":"https://git.kernel.org/stable/c/b6aecea4b2b246f9fbd98a5712daa1193a60818e"},{"url":"https://git.kernel.org/stable/c/2a5ac0c0f1f7da33929211a2e41911bf72ee35d8"},{"url":"https://git.kernel.org/stable/c/34f4feff3e90bd09308fad0974e97113b23b812a"}],"tags":["cve.org"],"epss":0.00176,"epssPercentile":0.06641,"ingestedAt":"2026-10-16T19:46:24.318Z","slug":"CVE-2026-80548","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Selectively expand io_mutex\n\nThe io_mutex was defined to serialize the io_regions, but then has\nalso sort of been associated with the I/O themselves because of\nthe close relationship they share.\n\nWith the handful of races that are possible, the choices are either to:\n A) expand the scope of io_mutex to close these remaining windows, or\n B) reduce the scope of io_mutex to just io_region, and introduce a new\n    lock mechanism for the remaining I/O resources\n\nThis patch implements A, since B brings with it a lot more interactions\nthat would need to be tracked and kept in a correct hierarchy. It also\ntakes advantage of the workqueue element for cp_free() that now gets\ncalled out of fsm_notoper(), which could be invoked out of an interrupt\ncontext and thus cannot acquire a mutex itself.\n\n## Affected\n\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < dab6a6627b0b0cce23653e99c7b0bf8c6cfd82e0`\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 56d7488533ceac4e986e96e15c9e487a2245bc01`\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < f72a51810d49411bd8cad0c2df8592320a2fe5cc`\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 2ba9efdf9ebedc4e54df4b56aa3b43a65f7967cd`\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < b6aecea4b2b246f9fbd98a5712daa1193a60818e`\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 2a5ac0c0f1f7da33929211a2e41911bf72ee35d8`\n- `Linux >= 4f76617378ee97c557b526cb58d3c61eb0a9c963 < 34f4feff3e90bd09308fad0974e97113b23b812a`\n- `Linux 5.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}