CVE-2026-31538 Details
Description
In the Linux kernel, the following vulnerability has been resolved: smb: server: make use of smbdirect_socket.recv_io.credits.available The logic off managing recv credits by counting posted recv_io and granted credits is racy. That's because the peer might already consumed a credit, but between receiving the incoming recv at the hardware and processing the completion in the 'recv_done' functions we likely have a window where we grant credits, which don't really exist. So we better have a decicated counter for the available credits, which will be incremented when we posted new recv buffers and drained when we grant the credits to the peer. This fixes regression Namjae reported with the 6.18 release.
A vulnerability in the Linux kernel's SMB server implementation has been addressed. The issue arose in the management of received credits over RDMA, where the logic was prone to race conditions. Specifically, credits could be incorrectly granted before they were fully processed, leading to a mismatch in available credits. This vulnerability affected Linux kernel versions 6.18.x. The issue has been resolved by introducing a dedicated counter for available credits, ensuring accurate tracking as new receive buffers are posted and credits are granted to the peer. This regression was reported by Namjae Jeon.
Users can upgrade to the latest version of the Linux kernel stable tree to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/26ad87a2cfb8c1384620d1693a166ed87303046e | kernel.org | Patch |
| https://git.kernel.org/stable/c/66c082e3d4651e8629a393a9e182b01eb50fb0a3 | kernel.org | Patch |
| https://git.kernel.org/stable/c/809cbd31aa4f87a1b889532244c9cf30eb022385 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| NVD-CWE-Other | Weakness Not in a Standard CWE Category | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.18, < 6.18.11 >= 6.19, < 6.19.1 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| Apr 28, 2026 | Initial Analysis | [email protected] |
| Apr 27, 2026 | CVE Modified | kernel.org |
| Apr 24, 2026 | New CVE Received | kernel.org |