{"id":"AZL-90842","summary":"CVE-2026-53239 affecting package kernel for versions less than 6.6.143.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()\n\nFix the race by pruning the bin while still holding xfrm_policy_lock,\nbefore dropping it. Use __xfrm_policy_inexact_prune_bin() directly since\nthe lock is already held. The wrapper xfrm_policy_inexact_prune_bin()\nbecomes unused and is removed.\n\nRace:\n\n  CPU0 (XFRM_MSG_DELPOLICY)           CPU1 (XFRM_MSG_NEWSPDINFO)\n  ==========================          ==========================\n  xfrm_policy_bysel_ctx():\n    spin_lock_bh(xfrm_policy_lock)\n    bin = xfrm_policy_inexact_lookup()\n    __xfrm_policy_unlink(pol)\n    spin_unlock_bh(xfrm_policy_lock)\n    xfrm_policy_kill(ret)\n    // wide window, lock not held\n                                       xfrm_hash_rebuild():\n                                         spin_lock_bh(xfrm_policy_lock)\n                                         __xfrm_policy_inexact_flush():\n                                           kfree_rcu(bin)  // bin freed\n                                         spin_unlock_bh(xfrm_policy_lock)\n    xfrm_policy_inexact_prune_bin(bin)\n    // UAF: bin is freed","modified":"2026-08-28T17:48:11.815898909Z","published":"2026-06-25T09:16:41Z","upstream":["CVE-2026-53239"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53239"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.143.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-90842.json"}}],"schema_version":"1.9.0"}