{"id":"AZL-90552","summary":"CVE-2026-53027 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked()\n\nWhen a compressed or sparse attribute has its clusters frame-aligned,\nvcn is rounded down to the frame start using cmask, which can result\nin vcn != vcn0. In this case, vcn and vcn0 may reside in different\nattribute segments.\n\nThe code already handles the case where vcn is in a different segment\nby loading its runs before allocation. However, it fails to load runs\nfor vcn0 when vcn0 resides in a different segment than vcn. This causes\nrun_lookup_entry() to return SPARSE_LCN for vcn0 since its segment was\nnever loaded into the in-memory run list, triggering the WARN_ON(1).\n\nFix this by adding a missing check for vcn0 after the existing vcn\nsegment check. If vcn0 falls outside the current segment range\n[svcn, evcn1), find and load the attribute segment containing vcn0\nbefore performing the run lookup.\n\nThe following scenario triggers the bug:\n  attr_data_get_block_locked()\n    vcn = vcn0 & cmask        \u003c- vcn != vcn0 after frame alignment\n    load runs for vcn segment \u003c- vcn0 segment not loaded!\n    attr_allocate_clusters()  \u003c- allocation succeeds\n    run_lookup_entry(vcn0)    \u003c- vcn0 not in run -\u003e SPARSE_LCN\n    WARN_ON(1)                \u003c- bug fires here!","modified":"2026-09-02T06:51:55Z","published":"2026-06-24T17:17:14Z","upstream":["CVE-2026-53027"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53027"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-90552.json"}}],"schema_version":"1.9.0"}