{"id":"CVE-2026-80550","summary":"s390/vfio_ccw: Fix out of bounds check on CCW array","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Fix out of bounds check on CCW array\n\nThe routine ccwchain_calc_length() counts the number of channel\ncommand words (CCWs) that are chained together in a single channel\nprogram, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs.\n\nThe loop itself is \"do..while (count \u003c 257)\", and while the logic in\nis_cpa_within_range() correctly adjusts between the 0-index array of\nCCWs and the count of CCWs starting at 1, this means it would look\nat a possible 257th CCW before ending the loop and (correctly)\nreturning an error.\n\nFix this by restructuring the loop to break as soon as 256 CCWs\n(thus indexes 0-255) are examined, without looking at memory\noutside the range.","modified":"2026-08-28T03:47:29.028883366Z","published":"2026-08-26T14:37:19.956Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80550.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0282fb1c4b638eecfe2cc558092c460911d8f7e2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/499a8a66b1598bfab97182aed15e0f1646074a3d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4c2e1d359d7a2b82cdf3254e4e480af9417f99fb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/907adc667d902fafbdb2d740d57b55bd025dc4cd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a005b7f1a491ffda61bff0fd0f6548f8986fb977"},{"type":"WEB","url":"https://git.kernel.org/stable/c/af3f80ca4c8b17f20f9e588def076288fdb49e65"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d5d096cd9369e986d4e5153baa86b8b35c283e09"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80550.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80550"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0a19e61e6d4c6192077ead760ba0a2d350987d4c"},{"fixed":"0282fb1c4b638eecfe2cc558092c460911d8f7e2"},{"fixed":"907adc667d902fafbdb2d740d57b55bd025dc4cd"},{"fixed":"f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3"},{"fixed":"af3f80ca4c8b17f20f9e588def076288fdb49e65"},{"fixed":"499a8a66b1598bfab97182aed15e0f1646074a3d"},{"fixed":"4c2e1d359d7a2b82cdf3254e4e480af9417f99fb"},{"fixed":"d5d096cd9369e986d4e5153baa86b8b35c283e09"},{"fixed":"a005b7f1a491ffda61bff0fd0f6548f8986fb977"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80550.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.12.0"},{"fixed":"5.10.266"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.217"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.184"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.153"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.105"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.46"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80550.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L"}]}