{"id":"CVE-2026-63889","title":"scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: scsi_transport_fc: Widen FPIN pname walker counter to u32\n\nAn adjacent Fibre Channel fabric actor that can deliver an FPIN ELS\nframe to an lpfc or qla2xxx Linux i…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 07776b7779c9426982c1ad74aad91bd531593790","Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 29f126f09e34a425b376b3646c89aa7cc18b142c","Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 163bd704d7515c3df6c2e03bcba93d1db79edbff","Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < ee57b89e5da9fffbe0d26647e4ff0750dacb9943","Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 35461d23744175a78b6280293892cca357c22793","Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770","Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153","Linux 5.11"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-16T15:33:03.386900Z"},"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:10.487Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-63889","references":[{"url":"https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790"},{"url":"https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c"},{"url":"https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff"},{"url":"https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943"},{"url":"https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793"},{"url":"https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770"},{"url":"https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153"}],"tags":["cve.org"],"epss":0.00358,"epssPercentile":0.28003,"ingestedAt":"2026-10-16T17:24:46.773Z","slug":"CVE-2026-63889","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nscsi: scsi_transport_fc: Widen FPIN pname walker counter to u32\n\nAn adjacent Fibre Channel fabric actor that can deliver an FPIN ELS\nframe to an lpfc or qla2xxx Linux initiator can trigger a non-return in\nthe generic FC transport. This is not a local userspace or IP network\npath; the attacker must be able to inject fabric traffic, for example as\na compromised switch or fabric controller, or as a same-zone N_Port on a\nfabric that permits source spoofing.\n\nThe Link-Integrity and Peer-Congestion FPIN walkers used a u8 loop\ncounter against the 32-bit on-wire pname_count field, and did not bound\npname_count by the descriptor body already validated by the TLV walker.\nA pname_count of 256 therefore wraps the counter and keeps the loop\ncondition true indefinitely.\n\nFactor the shared pname_list[] walk into one helper, widen the counter\nto u32, and clamp pname_count against the entries that fit in the\ndescriptor body before iterating.\n\n## Affected\n\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 07776b7779c9426982c1ad74aad91bd531593790`\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 29f126f09e34a425b376b3646c89aa7cc18b142c`\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 163bd704d7515c3df6c2e03bcba93d1db79edbff`\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < ee57b89e5da9fffbe0d26647e4ff0750dacb9943`\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < 35461d23744175a78b6280293892cca357c22793`\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770`\n- `Linux >= 3dcfe0de5a9752e646a61f4ce513ac059960c7c3 < a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153`\n- `Linux 5.11`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}