{"id":"AZL-50850","summary":"CVE-2024-49854 affecting package kernel for versions less than 6.6.56.1-5","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix uaf for accessing waker_bfqq after splitting\n\nAfter commit 42c306ed7233 (\"block, bfq: don't break merge chain in\nbfq_split_bfqq()\"), if the current procress is the last holder of bfqq,\nthe bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and\nthen access bfqq-\u003ewaker_bfqq may trigger UAF. What's more, the waker_bfqq\nmay in the merge chain of bfqq, hence just recored waker_bfqq is still\nnot safe.\n\nFix the problem by adding a helper bfq_waker_bfqq() to check if\nbfqq-\u003ewaker_bfqq is in the merge chain, and current procress is the only\nholder.","modified":"2026-04-01T05:16:20.494525Z","published":"2024-10-21T13:15:06Z","upstream":["CVE-2024-49854"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-49854"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.56.1-5"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-50850.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}