CVE-2026-31538 (GCVE-0-2026-31538)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:30 – Updated: 2026-04-24 14:30
VLAI?
Title
smb: server: make use of smbdirect_socket.recv_io.credits.available
Summary
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.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 89b021a72663c4d96d8a8b85272bb42d991a1c6f , < 66c082e3d4651e8629a393a9e182b01eb50fb0a3 (git)
Affected: 89b021a72663c4d96d8a8b85272bb42d991a1c6f , < 809cbd31aa4f87a1b889532244c9cf30eb022385 (git)
Affected: 89b021a72663c4d96d8a8b85272bb42d991a1c6f , < 26ad87a2cfb8c1384620d1693a166ed87303046e (git)
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    Linux Linux Affected: 6.18
Unaffected: 0 , < 6.18 (semver)
Unaffected: 6.18.11 , ≤ 6.18.* (semver)
Unaffected: 6.19.1 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: server: make use of smbdirect_socket.recv_io.credits.available\n\nThe logic off managing recv credits by counting posted recv_io and\ngranted credits is racy.\n\nThat\u0027s because the peer might already consumed a credit,\nbut between receiving the incoming recv at the hardware\nand processing the completion in the \u0027recv_done\u0027 functions\nwe likely have a window where we grant credits, which\ndon\u0027t really exist.\n\nSo we better have a decicated counter for the\navailable credits, which will be incremented\nwhen we posted new recv buffers and drained when\nwe grant the credits to the peer.\n\nThis fixes regression Namjae reported with\nthe 6.18 release."
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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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