{"id":"CVE-2023-54258","title":"cifs: fix potential oops in cifs_oplock_break","summary":"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 th…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 63fb45ddc491895c4b36664e0c2c3b548545ae93 < b99f490ea87ebcca3a429fd8837067feb56a4c7c","Linux >= 1bf709b9625001eefdd41048c5f4c7544ee33394 < 5ee28bcfbaacf289eb25c662a2862542ea6ce6a7","Linux >= 3b4c15171c3ce9120c81f5564b9367d8d0f4219c < 6b67a6d2e50634fe127e656147c81915955e9f5e","Linux >= da787d5b74983f7525d1eb4b9c0b4aff2821511a < e8f5f849ffce24490eb9449e98312b66c0dba76f","Linux cff7fb969edaeff2bc80c8a8f7cf7b0c8df32da7","Linux >= 6.3.13 < 6.4","Linux >= 5.15.121 < 5.15.128","Linux >= 6.1.39 < 6.1.47","Linux >= 6.4.4 < 6.4.12"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-15T21:39:50.673035Z"},"published":"2025-12-30","updated":"2026-10-15","sourceUpdated":"2026-10-15T21:41:43.411Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-54258","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"}],"tags":["cve.org"],"epss":0.00555,"epssPercentile":0.4509,"ingestedAt":"2026-10-15T22:48:25.436Z","slug":"CVE-2023-54258","body":"## Overview\n\nIn 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]  <TASK>\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]  </TASK>\n\nTo fix this change the ordering of the checks before sending the oplock_response\nto first check if the openFileList is empty.\n\n## Affected\n\n- `Linux >= 63fb45ddc491895c4b36664e0c2c3b548545ae93 < b99f490ea87ebcca3a429fd8837067feb56a4c7c`\n- `Linux >= 1bf709b9625001eefdd41048c5f4c7544ee33394 < 5ee28bcfbaacf289eb25c662a2862542ea6ce6a7`\n- `Linux >= 3b4c15171c3ce9120c81f5564b9367d8d0f4219c < 6b67a6d2e50634fe127e656147c81915955e9f5e`\n- `Linux >= da787d5b74983f7525d1eb4b9c0b4aff2821511a < e8f5f849ffce24490eb9449e98312b66c0dba76f`\n- `Linux cff7fb969edaeff2bc80c8a8f7cf7b0c8df32da7`\n- `Linux >= 6.3.13 < 6.4`\n- `Linux >= 5.15.121 < 5.15.128`\n- `Linux >= 6.1.39 < 6.1.47`\n- `Linux >= 6.4.4 < 6.4.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}