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CVE-2026-97557

smb: client: avoid leaking refcount in cifs_queue_oplock_break()

Products / packages Linux

Published

Share

Severity and exploitation

Not in CISA KEV

KEV coverage does not rule out exploitation.

KEV checked 14/11/2026, 21:00:34 UTC
Linux · CVSS:3.1 · 7.5
Assessment vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity

high7.5

CVSS measures technical severity, not the likelihood of an attack.

Known exploitation

Not listed in the checked CISA KEV catalog

Absence from CISA KEV does not rule out attacks.

Public exploit

Not established by this record

Missing evidence does not mean no public exploit exists.

Remediation

Fix status not established

No structured fix or guidance is available here. Check the latest publisher advisory.

What this means

In the Linux kernel, the following vulnerability has been resolved:

Source excerpt · Linux

Attack conditions

No attack-condition excerpt has been identified here. Review the full source description and references for authentication, network access, and configuration requirements.

Review supporting sources →

Affected versions

Check the exact model, release, and any platform requirements against your installation.

Linux · Linux

Linux

18 ranges
Linux version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

b98749cac4a695f084a5ff076f4510b23e353ecd → before 13b9519b19e6e58a6cd01e63062cd1da7bd6449a

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before 0fb92ac85db58945ad7b970ff17674001487b3a3

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before 735a3a610136ae10f381d0909dff38e5b5c5f056

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before de2a6bcff2659bea40c7485115b57f0ae189fc01

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before af0193bbf1ac8c0f67f972998b0cc629d6116cf6

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before 2ed2c29dd9593637cfa25ac1eb23241b20202778

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before dfe7b750c7e069873a8a57a11c816831a235618a

git versions

b98749cac4a695f084a5ff076f4510b23e353ecd → before 9f2e63f1b2d5fc5b5423424902c091123e220e7e

git versions

2429fcf06d3cb962693868ab0a927c9038f12a2d

git versions

1ee4f2d7cdcd4508cc3cbe3b2622d7177b89da12

git versions

53fc31a4853e30d6e8f142b824f724da27ff3e40

git versions

8092ecc306d81186a64cda42411121f4d35aaff4

git versions

ebac4d0adf68f8962bd82fcf483936edd6ec095b

git versions

3.16.72 → before 3.17

semver versions

4.9.171 → before 4.10

semver versions

4.14.114 → before 4.15

semver versions

4.19.37 → before 4.20

semver versions

5.0.10 → before 5.1

semver versions

unaffected

unknown

Other versions: unaffected

Linux · Linux

Linux

10 ranges
Linux version evidence

Compare with this publisher’s ranges. This does not inspect your installation.

affected

5.1

unaffected

0 → before 5.1

semver versions

5.10.273 → through 5.10.*

semver versions

5.15.224 → through 5.15.*

semver versions

6.1.189 → through 6.1.*

semver versions

6.6.158 → through 6.6.*

semver versions

6.12.111 → through 6.12.*

semver versions

6.18.53 → through 6.18.*

semver versions

7.2.7 → through 7.2.*

semver versions

7.3 → through *

original_commit_for_fix versions

unknown

Other versions: affected

Automatic dependency matching is unavailable for this record. Use the product evidence and publisher’s instructions to check your installation.

What to do

Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.

No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.

cve.new guidance unless attributed to a publisher. This page does not inspect your installation.

Public exploit evidence

No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.

Original source description

Read the full publisher 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.

References

8 sources
git.kernel.org/stable/c/13b9519b19e6e58a6cd01e63062cd1da7bd6449a
Source referenceLinux
git.kernel.org/stable/c/0fb92ac85db58945ad7b970ff17674001487b3a3
Source referenceLinux
git.kernel.org/stable/c/735a3a610136ae10f381d0909dff38e5b5c5f056
Source referenceLinux
git.kernel.org/stable/c/de2a6bcff2659bea40c7485115b57f0ae189fc01
Source referenceLinux
git.kernel.org/stable/c/af0193bbf1ac8c0f67f972998b0cc629d6116cf6
Source referenceLinux
git.kernel.org/stable/c/2ed2c29dd9593637cfa25ac1eb23241b20202778
Source referenceLinux
View 2 more references
git.kernel.org/stable/c/dfe7b750c7e069873a8a57a11c816831a235618a
Source referenceLinux
git.kernel.org/stable/c/9f2e63f1b2d5fc5b5423424902c091123e220e7e
Source referenceLinux

Inside the record

Evidence available

Package identity · not supplied
Version evidence
Remediation guidance · not supplied
Weakness classification · not supplied
Additional publishers · not supplied

Describes the evidence in this view, not whether the product is safe.

Original records

CVE-2026-97557

View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.

cve.new JSON →

Environment requirements

These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.

Linux · platform conditions

Any condition may hold

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 5.10.273

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 5.15.224

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 6.1.189

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 6.6.158

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 6.12.111

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 6.18.53

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 7.2.7

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.1

Before: 7.3

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 3.16.72

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.9.171

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.14.114

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 4.19.37

Vulnerable product

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

From (inclusive): 5.0.10

Applicability preview
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  {
    "nodes": [
      {
        "operator": "OR",
        "negate": false,
        "cpeMatch": [
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "5.1",
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          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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          {
            "vulnerable": true,
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            "vulnerable": true,
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            "versionStartIncluding": "5.1",
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          {
            "vulnerable": true,
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          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "3.16.72"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.9.171"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.14.114"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "4.19.37"
          },
          {
            "vulnerable": true,
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionStartIncluding": "5.0.10"
          }
        ]
      }
    ]
  }
]
Contributing organizations · 1
Linux

Assigning organization

2026-10-30

Timeline

All times UTC

  1. Advisory published

    Publication date supplied by the source.

  2. Source updated

    Latest modification date supplied by the source.

  3. Last imported by cve.new

    Latest catalog import, not the date we first saw this advisory.

What changed

Follow changes
No substantive changes have been recorded here yet. History starts when cve.new observes a change after tracking is enabled; earlier edits are not reconstructed.

Large field values are marked as truncated previews. Original source snapshots remain retained.