GHSA-52G3-8W7F-V5W2
Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-10-30 15:33In the Linux kernel, the following vulnerability has been resolved:
ksmbd: detach blocked lock requests before freeing
A file_lock retained by ksmbd for byte-range lock bookkeeping can still be part of the VFS blocked-request graph. In particular, the VFS can chain a new waiter below an already blocked request through flc_blocked_requests. The ksmbd_file reference count does not cover that graph.
Both __ksmbd_close_fd() and the cross-request unlock path free these retained file_lock objects directly. If a dependent waiter is still attached, locks_release_private() hits BUG_ON(!list_empty(&flc->flc_blocked_requests)). The same lifetime mismatch can leave a freed ksmbd_lock reachable through its request-local llist.
Detach the file_lock from the blocked-request graph before freeing it in the close, cross-request unlock, and rollback paths. locks_delete_block() also wakes requests chained below the object. Remove llist when a completed lock is published so a globally visible ksmbd_lock no longer points into the submitting worker's stack.
{
"affected": [],
"aliases": [
"CVE-2026-90155"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-17T17:17:08Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: detach blocked lock requests before freeing\n\nA file_lock retained by ksmbd for byte-range lock bookkeeping can still\nbe part of the VFS blocked-request graph. In particular, the VFS can\nchain a new waiter below an already blocked request through\nflc_blocked_requests. The ksmbd_file reference count does not cover that\ngraph.\n\nBoth __ksmbd_close_fd() and the cross-request unlock path free these\nretained file_lock objects directly. If a dependent waiter is still\nattached, locks_release_private() hits\nBUG_ON(!list_empty(\u0026flc-\u003eflc_blocked_requests)). The same lifetime\nmismatch can leave a freed ksmbd_lock reachable through its request-local\nllist.\n\nDetach the file_lock from the blocked-request graph before freeing it in\nthe close, cross-request unlock, and rollback paths. locks_delete_block()\nalso wakes requests chained below the object. Remove llist when a\ncompleted lock is published so a globally visible ksmbd_lock no longer\npoints into the submitting worker\u0027s stack.",
"id": "GHSA-52g3-8w7f-v5w2",
"modified": "2026-10-30T15:33:33Z",
"published": "2026-09-17T18:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90155"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/215e8816b1ac25176d911abb8704390413ccee4b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4e8b69c06bd6583ec11abef4fae50c2c8d5f3679"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/514a0b2bc949963497e66cacd433f65dc768a71d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d31db79cfaa9fce6649772ad279779473ba8aef9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f77d2accafca529e0ea3f979eb6e6cf1dac05c90"
}
],
"schema_version": "1.4.0",
"severity": []
}
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