{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-54258", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-30T12:06:44.516Z", "datePublished": "2025-12-30T12:15:52.855Z", "dateUpdated": "2026-08-05T09:18:36.889Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:18:36.889Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix potential oops in cifs_oplock_break\n\nWith deferred close we can have closes that race with lease breaks,\nand so with the current checks for whether to send the lease response,\noplock_response(), this can mean that an unmount (kill_sb) can occur\njust before we were checking if the tcon->ses is valid. See below:\n\n[Fri Aug 4 04:12:50 2023] RIP: 0010:cifs_oplock_break+0x1f7/0x5b0 [cifs]\n[Fri Aug 4 04:12:50 2023] Code: 7d a8 48 8b 7d c0 c0 e9 02 48 89 45 b8 41 89 cf e8 3e f5 ff ff 4c 89 f7 41 83 e7 01 e8 82 b3 03 f2 49 8b 45 50 48 85 c0 74 5e <48> 83 78 60 00 74 57 45 84 ff 75 52 48 8b 43 98 48 83 eb 68 48 39\n[Fri Aug 4 04:12:50 2023] RSP: 0018:ffffb30607ddbdf8 EFLAGS: 00010206\n[Fri Aug 4 04:12:50 2023] RAX: 632d223d32612022 RBX: ffff97136944b1e0 RCX: 0000000080100009\n[Fri Aug 4 04:12:50 2023] RDX: 0000000000000001 RSI: 0000000080100009 RDI: ffff97136944b188\n[Fri Aug 4 04:12:50 2023] RBP: ffffb30607ddbe58 R08: 0000000000000001 R09: ffffffffc08e0900\n[Fri Aug 4 04:12:50 2023] R10: 0000000000000001 R11: 000000000000000f R12: ffff97136944b138\n[Fri Aug 4 04:12:50 2023] R13: ffff97149147c000 R14: ffff97136944b188 R15: 0000000000000000\n[Fri Aug 4 04:12:50 2023] FS: 0000000000000000(0000) GS:ffff9714f7c00000(0000) knlGS:0000000000000000\n[Fri Aug 4 04:12:50 2023] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[Fri Aug 4 04:12:50 2023] CR2: 00007fd8de9c7590 CR3: 000000011228e000 CR4: 0000000000350ef0\n[Fri Aug 4 04:12:50 2023] Call Trace:\n[Fri Aug 4 04:12:50 2023] \n[Fri Aug 4 04:12:50 2023] process_one_work+0x225/0x3d0\n[Fri Aug 4 04:12:50 2023] worker_thread+0x4d/0x3e0\n[Fri Aug 4 04:12:50 2023] ? process_one_work+0x3d0/0x3d0\n[Fri Aug 4 04:12:50 2023] kthread+0x12a/0x150\n[Fri Aug 4 04:12:50 2023] ? set_kthread_struct+0x50/0x50\n[Fri Aug 4 04:12:50 2023] ret_from_fork+0x22/0x30\n[Fri Aug 4 04:12:50 2023] \n\nTo fix this change the ordering of the checks before sending the oplock_response\nto first check if the openFileList is empty." } ], "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 - The oplock/lease break is an unsolicited SMB2 notification packet received from the remote server and processed by the cifs demultiplex thread (`is_oplock_break` → `cifs_queue_oplock_break`), so a malicious/compromised SMB server or an MITM on a non-signed connection triggers the vulnerable work item purely over the network. This matches the treatment of other cifs client bugs driven by server-supplied data, including the identical CVE-2025-38527 in this same function.\nAC:L - The remote server controls the triggering side entirely and can send lease/oplock breaks continuously, and the same break drives `cifs_close_deferred_file()` on the other side; with the last handle the `kfree(tcon)` occurs synchronously inside `_cifsFileInfo_put()` rather than through a narrow window, and unmounts occur automatically in common autofs/automount deployments.\nPR:N - The attacker is the SMB server (or an MITM) and needs no credentials or privileges on the victim client; the client's own handling of a server-sent break notification is what enters the vulnerable path.\nUI:N - Against an already-mounted share the attack needs no victim action — the server sends break notifications on its own schedule and the teardown side is reached via deferred-close plus automatic/idle unmount rather than an interactive step.\nS:U - The use-after-free is in kernel memory and its impact stays within the kernel's own security authority, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The freed `struct cifs_tcon` is dereferenced through a four-level pointer chain (`tcon->ses->server->ops`) read from reallocated slab contents, which after heap grooming yields an arbitrary kernel read primitive; the oops itself shows the freed object already refilled with unrelated heap data.\nI:H - The stale pointer terminates in an indirect call `tcon->ses->server->ops->oplock_response(tcon, ...)` where every pointer in the chain and the first argument come from freed, reallocatable memory, giving a control-flow hijack primitive and thus arbitrary kernel code execution.\nA:H - Even unexploited, the bug produces an immediate kernel oops (general protection fault from the non-canonical `ses` pointer in the reported trace), and it can be re-triggered repeatedly by the remote server." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/file.c" ], "versions": [ { "version": "63fb45ddc491895c4b36664e0c2c3b548545ae93", "lessThan": "b99f490ea87ebcca3a429fd8837067feb56a4c7c", "status": "affected", "versionType": "git" }, { "version": "1bf709b9625001eefdd41048c5f4c7544ee33394", "lessThan": "5ee28bcfbaacf289eb25c662a2862542ea6ce6a7", "status": "affected", "versionType": "git" }, { "version": "3b4c15171c3ce9120c81f5564b9367d8d0f4219c", "lessThan": "6b67a6d2e50634fe127e656147c81915955e9f5e", "status": "affected", "versionType": "git" }, { "version": "da787d5b74983f7525d1eb4b9c0b4aff2821511a", "lessThan": "e8f5f849ffce24490eb9449e98312b66c0dba76f", "status": "affected", "versionType": "git" }, { "version": "cff7fb969edaeff2bc80c8a8f7cf7b0c8df32da7", "status": "affected", "versionType": "git" }, { "version": "6.3.13", "lessThan": "6.4", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/file.c" ], "versions": [ { "version": "5.15.121", "lessThan": "5.15.128", "status": "affected", "versionType": "semver" }, { "version": "6.1.39", "lessThan": "6.1.47", "status": "affected", "versionType": "semver" }, { "version": "6.4.4", "lessThan": "6.4.12", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.121", "versionEndExcluding": "5.15.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.39", "versionEndExcluding": "6.1.47" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.4", "versionEndExcluding": "6.4.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b99f490ea87ebcca3a429fd8837067feb56a4c7c" }, { "url": "https://git.kernel.org/stable/c/5ee28bcfbaacf289eb25c662a2862542ea6ce6a7" }, { "url": "https://git.kernel.org/stable/c/6b67a6d2e50634fe127e656147c81915955e9f5e" }, { "url": "https://git.kernel.org/stable/c/e8f5f849ffce24490eb9449e98312b66c0dba76f" } ], "title": "cifs: fix potential oops in cifs_oplock_break", "x_generator": { "engine": "bippy-1.2.0" } } } }