Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected b98749cac4a695f084a5ff076f4510b23e353ecd before 735a3a610136ae10f381d0909dff38e5b5c5f056; affected b98749cac4a695f084a5ff076f4510b23e353ecd before de2a6bcff2659bea40c7485115b57f0ae189fc01; affected b98749cac4a695f084a5ff076f4510b23e353ecd before af0193bbf1ac8c0f67f972998b0cc629d6116cf6; affected b98749cac4a695f084a5ff076f4510b23e353ecd before 2ed2c29dd9593637cfa25ac1eb23241b20202778; affected b98749cac4a695f084a5ff076f4510b23e353ecd before dfe7b750c7e069873a8a57a11c816831a235618a; affected b98749cac4a695f084a5ff076f4510b23e353ecd before 9f2e63f1b2d5fc5b5423424902c091123e220e7e; affected 2429fcf06d3cb962693868ab0a927c9038f12a2d; affected 1ee4f2d7cdcd4508cc3cbe3b2622d7177b89da12; affected 53fc31a4853e30d6e8f142b824f724da27ff3e40; affected 8092ecc306d81186a64cda42411121f4d35aaff4; affected ebac4d0adf68f8962bd82fcf483936edd6ec095b; affected 3.16.72 before 3.17; affected 4.9.171 before 4.10; affected 4.14.114 before 4.15; affected 4.19.37 before 4.20; affected 5.0.10 before 5.1 |
| Linux / Linux | affected 5.1; unaffected 0 before 5.1; unaffected 6.1.189 through 6.1.*; unaffected 6.6.158 through 6.6.*; unaffected 6.12.111 through 6.12.*; unaffected 6.18.53 through 6.18.*; unaffected 7.2.7 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/735a3a610136ae10f381d0909dff38e5b5c5f056
- https://git.kernel.org/stable/c/de2a6bcff2659bea40c7485115b57f0ae189fc01
- https://git.kernel.org/stable/c/af0193bbf1ac8c0f67f972998b0cc629d6116cf6
- https://git.kernel.org/stable/c/2ed2c29dd9593637cfa25ac1eb23241b20202778
- https://git.kernel.org/stable/c/dfe7b750c7e069873a8a57a11c816831a235618a
- https://git.kernel.org/stable/c/9f2e63f1b2d5fc5b5423424902c091123e220e7e