{"id":"AZL-83879","summary":"CVE-2026-31597 affecting package kernel for versions less than 6.6.137.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY\n\nfilemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY,\nas documented in mm/filemap.c:\n\n  \"If our return value has VM_FAULT_RETRY set, it's because the mmap_lock\n  may be dropped before doing I/O or by lock_folio_maybe_drop_mmap().\"\n\nWhen this happens, a concurrent munmap() can call remove_vma() and free\nthe vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then\nbecomes a dangling pointer, and the subsequent trace_ocfs2_fault() call\ndereferences it -- a use-after-free.\n\nFix this by saving ip_blkno as a plain integer before calling\nfilemap_fault(), and removing vma from the trace event. Since\nip_blkno is copied by value before the lock can be dropped, it\nremains valid regardless of what happens to the vma or inode\nafterward.","modified":"2026-08-28T17:48:03.449560164Z","published":"2026-04-24T15:16:37Z","upstream":["CVE-2026-31597"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31597"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.137.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-83879.json"}}],"schema_version":"1.9.0"}