Answer in brief
CVE-2026-97557 records a High severity (CVSS 7.5) vulnerability in smb: client: avoid leaking refcount in cifs_queue_oplock_break(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=b98749cac4a695f084a5ff076f4510b23e353ecd <af0193bbf1ac8c0f67f972998b0cc629d6116cf6 || >=b98749cac4a695f084a5ff076f4510b23e353ecd <2ed2c29dd9593637cfa25ac1eb23241b20202778 || >=b98749cac4a695f084a5ff076f4510b23e353ecd <dfe7b750c7e069873a8a57a11c816831a235618a || >=b98749cac4a695f084a5ff076f4510b23e353ecd <9f2e63f1b2d5fc5b5423424902c091123e220e7e || 2429fcf06d3cb962693868ab0a927c9038f12a2d || 1ee4f2d7cdcd4508cc3cbe3b2622d7177b89da12 || 53fc31a4853e30d6e8f142b824f724da27ff3e40 || 8092ecc306d81186a64cda42411121f4d35aaff4 || ebac4d0adf68f8962bd82fcf483936edd6ec095b || >=3.16.72 <3.17 || >=4.9.171 <4.10 || >=4.14.114 <4.15 || >=4.19.37 <4.20 || >=5.0.10 <5.1 | af0193bbf1ac8c0f67f972998b0cc629d6116cf6, 2ed2c29dd9593637cfa25ac1eb23241b20202778, dfe7b750c7e069873a8a57a11c816831a235618a, 9f2e63f1b2d5fc5b5423424902c091123e220e7e, 3.17, 4.10, 4.15, 4.20, 5.1 |
| Linux/Linuxgeneric | 5.1 | Not reported |
Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 25, 2026
In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid leaking refcount in cifs_queue_oplock_break() cifs_queue_oplock_break() unconditionally takes a reference on the target file before queueing cifs_oplock_break(). Only that work item decreases the reference counter again. If another oplock break arrives while that work is still queued, queue_work() will return false and not queue this second work item. As a result, we will never reach the point to drop the file reference again and are leaking this reference. This can be triggered when interacting with a slow-responding server. As a result, later unmount operations for this file system will fail with BUG: Dentry ... still in use (1) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) kernel BUG at fs/super.c:777! Fix this by only incrementing the reference count if the work has been queued successfully. Taking it after queue_work() is safe because all three callers hold tcon->open_file_lock across the call and _cifsFileInfo_put() decrements under that same lock, so a worker that starts the handler in the window cannot drop the reference before it has been taken.
Quoted source text, attributed separately from HOL analysis.