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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-97557

smb: client: avoid leaking refcount in cifs_queue_oplock_break()

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Status
Published
Published
Updated
Assigning organization
Linux

Description

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 products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b98749cac4a695f084a5ff076f4510b23e353ecd to < 735a3a610136ae10f381d0909dff38e5b5c5f056affected
  • b98749cac4a695f084a5ff076f4510b23e353ecd to < de2a6bcff2659bea40c7485115b57f0ae189fc01affected
  • b98749cac4a695f084a5ff076f4510b23e353ecd to < af0193bbf1ac8c0f67f972998b0cc629d6116cf6affected
  • b98749cac4a695f084a5ff076f4510b23e353ecd to < 2ed2c29dd9593637cfa25ac1eb23241b20202778affected
  • b98749cac4a695f084a5ff076f4510b23e353ecd to < dfe7b750c7e069873a8a57a11c816831a235618aaffected
  • b98749cac4a695f084a5ff076f4510b23e353ecd to < 9f2e63f1b2d5fc5b5423424902c091123e220e7eaffected
  • 2429fcf06d3cb962693868ab0a927c9038f12a2daffected
  • 1ee4f2d7cdcd4508cc3cbe3b2622d7177b89da12affected
  • 53fc31a4853e30d6e8f142b824f724da27ff3e40affected
  • 8092ecc306d81186a64cda42411121f4d35aaff4affected
  • ebac4d0adf68f8962bd82fcf483936edd6ec095baffected
  • 3.16.72 to < 3.17affected
  • 4.9.171 to < 4.10affected
  • 4.14.114 to < 4.15affected
  • 4.19.37 to < 4.20affected
  • 5.0.10 to < 5.1affected

Linux Linux

Default version status: affected

  • 5.1affected
  • 0 to < 5.1unaffected
  • 6.1.189 to ≤ 6.1.*unaffected
  • 6.6.158 to ≤ 6.6.*unaffected
  • 6.12.111 to ≤ 6.12.*unaffected
  • 6.18.53 to ≤ 6.18.*unaffected
  • 7.2.7 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References