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TI-2026-64187 Aliases CVE-2026-97557GHSA-v47h-9mpw-4682

smb: client: avoid leaking refcount in cifs_queue_oplock_break()

Priority LOW 34Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

EPSS 0.00696 53rd percentileScored 2026-11-07
Fix Partial Linux (Linux): 3.17, 4.10, 4.15 +10Red Hat: 5 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux3.16.72 to before 3.17; 4.9.171 to before 4.10; 4.14.114 to before 4.15; 4.19.37 to before 4.20; 5.0.10 to before 5.13.17, 4.10, 4.15, 4.20, 5.1Patch availableCNA
LinuxLinux5.1 and later5.10.273, 5.15.224, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2.7, 7.3Patch availableCNA
  • Linux VendorLinux Affected 3.16.72 to before 3.17; 4.9.171 to before 4.10; 4.14.114 to before 4.15; 4.19.37 to before 4.20; 5.0.10 to before 5.1 Fixed in 3.17, 4.10, 4.15, 4.20, 5.1 Patch available CNA
  • Linux VendorLinux Affected 5.1 and later Fixed in 5.10.273, 5.15.224, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2.7, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 3.17, 4.10, 4.15, 4.20, 5.1
  • Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.2.7, 7.3

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-97557
  2. 2026-10-03 Alias added: GHSA-v47h-9mpw-4682
  3. 2026-10-03 Fix available: Linux/[email protected], Linux/[email protected], Linux/Linux@735a3a610136ae10f381d0909dff38e5b5c5f056 +1 · CNA
  4. 2026-10-03 2 new references · CNA
  5. 2026-10-13 EPSS moved to the 50th–90th percentile
  6. 2026-10-19 Fix available: Linux/[email protected] · CNA
  7. 2026-10-21 Affected versions changed · Red Hat
  8. 2026-10-21 CVSS score changed · Red Hat
  9. 2026-10-30 Fix available: Linux/Linux@0fb92ac85db58945ad7b970ff17674001487b3a3, Linux/Linux@13b9519b19e6e58a6cd01e63062cd1da7bd6449a, Linux/[email protected] +1 · CNA
  10. 2026-10-30 2 new references · CNA
  11. 2026-10-30 Affected versions changed · Red Hat

References

Other 8

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences