{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68381", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.387Z", "datePublished": "2026-08-10T12:03:59.849Z", "dateUpdated": "2026-08-17T05:04:27.523Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:04:27.523Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: pin conn during async oplock break notification\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn\npointer in an async ksmbd_work and then queue that work on ksmbd-io. The\nwork only increments conn->r_count, which prevents teardown from passing\nthe pending-request wait after the increment, but it does not pin the\nstruct ksmbd_conn object.\n\nIf connection teardown races with an oplock break notification, the last\nconn reference can be dropped before the queued worker finishes. The\nworker then uses the freed conn in ksmbd_conn_write() and\nksmbd_conn_r_count_dec().\n\nTake a real conn reference when publishing the conn pointer to the async\nwork item, and drop it after the notification work has decremented\nr_count. Apply the same lifetime rule to lease break notification, which\nuses the same work->conn pattern." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - ksmbd is the in-kernel SMB server listening on TCP/445 (and SMB-Direct); the oplock/lease break notification path is driven entirely by remote SMB2 CREATE/close traffic and connection teardown, so a remote peer reaches the freed-conn use over the network.\nAC:L - The attacker controls both sides of the race: one connection holds a batch oplock/lease while a second connection opens the same file to force the async break, and the first connection is then abruptly dropped so teardown passes the r_count wait before the increment lands; this can be retried across arbitrarily many connections.\nPR:N - ksmbd share access is commonly exposed with guest/anonymous mapping, so an unauthenticated or trivially-credentialed remote client can open files and trigger oplock/lease breaks; consistent with prior ksmbd connection-lifetime UAF scoring, no meaningful privilege gate protects this path.\nUI:N - No victim action is needed; the attacker's own two SMB connections create the oplock break and the racing disconnect entirely on their own initiative.\nS:U - The freed object and the corrupted state are both kernel memory owned by the ksmbd server within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Use-after-free of struct ksmbd_conn lets the attacker reclaim the slab object with attacker-shaped data and have the worker read conn->transport and response state from it, enabling disclosure of kernel memory and pointer values, potentially leaked back over the SMB connection.\nI:H - ksmbd_conn_write() dereferences conn->transport->ops->writev from the freed object and indirectly calls it, and ksmbd_conn_lock()/ksmbd_conn_r_count_dec() perform mutex and atomic/waitqueue writes into freed memory, giving heap-spray-based control-flow hijack and arbitrary-write potential.\nA:H - Even without successful exploitation, using a freed ksmbd_conn (mutex operations, transport pointer dereference, waitqueue wakeup) reliably causes memory corruption, oops, or kernel panic, taking down the whole system." } ] } ], "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": "09aeab68033161cb54f194da93e51a11aee6144b", "lessThan": "0f72fc9659d7f585460d43c158055df5afdcffb6", "status": "affected", "versionType": "git" }, { "version": "a4261bbc33fbf99b99c80aa3a2c5097611802980", "lessThan": "793e1c7041b93af96ff87e678329bc16aee7ba88", "status": "affected", "versionType": "git" }, { "version": "3aa660c059240e0c795217182cf7df32909dd917", "lessThan": "6ecb252efa0b413ac3d9979fb4eec247f8fc1258", "status": "affected", "versionType": "git" }, { "version": "3aa660c059240e0c795217182cf7df32909dd917", "lessThan": "14062c74e5b25c27edcff7a2fe0dc701c930b372", "status": "affected", "versionType": "git" }, { "version": "3aa660c059240e0c795217182cf7df32909dd917", "lessThan": "aa5d8f3f96aa11a4a54ce993c11ce8af11c546f9", "status": "affected", "versionType": "git" }, { "version": "f17d1c63a76b0fe8e9c78023a86507a3a6d62cfa", "status": "affected", "versionType": "git" }, { "version": "6.6.84", "lessThan": "6.6.148", "status": "affected", "versionType": "semver" }, { "version": "6.12.20", "lessThan": "6.12.101", "status": "affected", "versionType": "semver" }, { "version": "6.13.8", "lessThan": "6.14", "status": "affected", "versionType": "semver" } ] }, { "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": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "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": "6.6.84", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.20", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0f72fc9659d7f585460d43c158055df5afdcffb6" }, { "url": "https://git.kernel.org/stable/c/793e1c7041b93af96ff87e678329bc16aee7ba88" }, { "url": "https://git.kernel.org/stable/c/6ecb252efa0b413ac3d9979fb4eec247f8fc1258" }, { "url": "https://git.kernel.org/stable/c/14062c74e5b25c27edcff7a2fe0dc701c930b372" }, { "url": "https://git.kernel.org/stable/c/aa5d8f3f96aa11a4a54ce993c11ce8af11c546f9" } ], "title": "ksmbd: pin conn during async oplock break notification", "x_generator": { "engine": "bippy-1.2.0" } } } }