# CVE-2026-68381: ksmbd: pin conn during async oplock break notification

CVE-2026-68381 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-68381, released August 11, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-68381
- Priority: High
- CVSS: 9.8 (Moderate)
- EPSS: 0.0049
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 10, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68381

## Description

In the Linux kernel, the following vulnerability has been resolved:  ksmbd: pin conn during async oplock break notification  smb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn pointer in an async ksmbd_work and then queue that work on ksmbd-io.  The work only increments conn->r_count, which prevents teardown from passing the pending-request wait after the increment, but it does not pin the struct ksmbd_conn object.  If connection teardown races with an oplock break notification, the last conn reference can be dropped before the queued worker finishes.  The worker then uses the freed conn in ksmbd_conn_write() and ksmbd_conn_r_count_dec().  Take a real conn reference when publishing the conn pointer to the async work item, and drop it after the notification work has decremented r_count.  Apply the same lifetime rule to lease break notification, which uses the same work->conn pattern.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 13.5 (trixie) | 6.12.101-1 | [DEBIAN-CVE-2026-68381](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68381.md) | Aug 11, 2026 |
| Linux | linux Debian 14 | 7.1.6-1 | [DEBIAN-CVE-2026-68381](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68381.md) | Aug 11, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.101-1~deb12u1 | [DEBIAN-CVE-2026-68381](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68381.md) | Aug 11, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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