{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72492", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.936Z", "datePublished": "2026-08-15T05:57:26.967Z", "dateUpdated": "2026-08-17T05:44:53.329Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:44:53.329Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in same_client_has_lease()\n\nsame_client_has_lease() returns an opinfo pointer from ci->m_op_list\nafter dropping ci->m_lock without taking a reference.\n\nsmb_grant_oplock() then dereferences that pointer in copy_lease() and\nwhen checking breaking_cnt. A concurrent close can remove the old lease\nfrom ci->m_op_list and drop the last reference before the caller uses\nthe returned pointer, leading to a use-after-free.\n\nTake a reference when same_client_has_lease() selects an existing lease,\ndrop any previous match while scanning, and release the returned\nreference in smb_grant_oplock() after copying the lease state." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - ksmbd is the in-kernel SMB server on TCP/445; the UAF is reached when a remote client sends SMB2_CREATE with a lease context, handled via ksmbd_conn_handler_loop() through smb2_open() and smb_grant_oplock() into same_client_has_lease().\nAC:L - The attacker controls both sides of the race by holding a leased open on one SMB connection while concurrently issuing SMB2_CREATE (lease upgrade) and SMB2_CLOSE on another connection or channel; no victim-dependent timing or memory layout is required.\nPR:L - Exploitation requires a valid SMB2 session, tree connect, and share permission to open/close the target file with SMB3 leasing enabled; smb2_check_user_session() rejects SMB2_CREATE without SMB2_SESSION_VALID, so this is not reachable on pre-authentication negotiate/echo paths.\nUI:N - No victim interaction is required; the attacker drives all SMB2_CREATE and SMB2_CLOSE operations on their own client connection(s) to trigger the concurrent lease lookup and file close.\nS:U - Impact is kernel heap corruption and privilege escalation on the SMB server host within the ksmbd/kernel security authority; it does not cross a VM, container, or IOMMU boundary.\nC:H - Use-after-free of a freed oplock_info/lease object in copy_lease() reads attacker-influenced slab contents (level, lease state, keys, flags, epoch), enabling kernel memory disclosure and arbitrary-read primitive construction.\nI:H - The UAF dereferences freed oplock_info and embedded lease pointers during copy_lease() and breaking_cnt checks, enabling heap grooming and memory corruption exploitable for arbitrary write or control-flow hijack as root.\nA:H - Concurrent close can free the oplock_info before smb_grant_oplock() uses it, causing reliable kernel memory corruption, oops, or panic and repeatable remote denial of service against the server." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/oplock.c" ], "versions": [ { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "aaa3bb2bbf2ccbfea9e4e0b9dabf3afc60b50cd0", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "09634cd055d9bd8dd167995ea52bcd8028dd5dac", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "7c3264d273d524aa6adcce23c01087271f13586f", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "79c7c59bb519db6f5a2a151965e825ec725614cc", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "35d3d6ff2bc1e7aaecb15d5377ebbd6227acae0d", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "0ff82a9cf9312678d8bc4edeef0b6e82659ac12a", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "65b655f65c3ca1ab5d598d3832bb0ff531725858", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/oplock.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/aaa3bb2bbf2ccbfea9e4e0b9dabf3afc60b50cd0" }, { "url": "https://git.kernel.org/stable/c/09634cd055d9bd8dd167995ea52bcd8028dd5dac" }, { "url": "https://git.kernel.org/stable/c/7c3264d273d524aa6adcce23c01087271f13586f" }, { "url": "https://git.kernel.org/stable/c/79c7c59bb519db6f5a2a151965e825ec725614cc" }, { "url": "https://git.kernel.org/stable/c/35d3d6ff2bc1e7aaecb15d5377ebbd6227acae0d" }, { "url": "https://git.kernel.org/stable/c/0ff82a9cf9312678d8bc4edeef0b6e82659ac12a" }, { "url": "https://git.kernel.org/stable/c/65b655f65c3ca1ab5d598d3832bb0ff531725858" } ], "title": "ksmbd: fix use-after-free in same_client_has_lease()", "x_generator": { "engine": "bippy-1.2.0" } } } }