CVE-2026-31535 PUBLISHED

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

Assigner: Linux
Reserved: 09.03.2026 Published: 24.04.2026 Updated: 24.04.2026

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

smb: client: 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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 5fb9b459b3686e366640edd4e62805ef7b4de927 to f664e6e8a81103cb45c8802a9bc7499e0902c458 (excl.)
  • affected from 5fb9b459b3686e366640edd4e62805ef7b4de927 to be8845ad5d6558703d20567d8702155598325db8 (excl.)
  • affected from 5fb9b459b3686e366640edd4e62805ef7b4de927 to 9911b1ed187a770a43950bf51f340ad4b7beecba (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.18 is affected
  • unaffected from 0 to 6.18 (excl.)
  • unaffected from 6.18.11 to 6.18.* (incl.)
  • unaffected from 6.19.1 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References