Riskcovery

CVE-2026-31538

smb: server: make use of smbdirect_socket.recv_io.credits.available

State
Published
Severity
7.5 High
Published
Apr 24, 2026
Updated
Aug 5, 2026
Reserved
Mar 9, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 89b021a72663c4d96d8a8b85272bb42d991a1c6f to before 66c082e3d4651e8629a393a9e182b01eb50fb0a3Affected
  • 89b021a72663c4d96d8a8b85272bb42d991a1c6f to before 809cbd31aa4f87a1b889532244c9cf30eb022385Affected
  • 89b021a72663c4d96d8a8b85272bb42d991a1c6f to before 26ad87a2cfb8c1384620d1693a166ed87303046eAffected
LinuxLinux
  • 6.18Affected
  • before 6.18Not affected
  • 6.18.11 through 6.18.*Not affected
  • 6.19.1 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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