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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 24 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
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.
Title smb: server: make use of smbdirect_socket.recv_io.credits.available
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-04-24T14:30:25.598Z

Reserved: 2026-03-09T15:48:24.113Z

Link: CVE-2026-31538

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-24T15:16:27.740

Modified: 2026-04-24T17:51:40.810

Link: CVE-2026-31538

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.