{"id":"CVE-2026-31539","title":"smb: smbdirect: introduce smbdirect_socket.recv_io.credits.available","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: smbdirect: introduce 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'…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 5fb9b459b3686e366640edd4e62805ef7b4de927 < e811e60e1cc79923c4388146eb1fa26a7482731e","Linux >= 5fb9b459b3686e366640edd4e62805ef7b4de927 < f99996870222b598914a1f49d7375dc23752c237","Linux >= 5fb9b459b3686e366640edd4e62805ef7b4de927 < 6e3c5052f9686192e178806e017b7377155f4bab","Linux 6.18"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T15:10:46.426998Z"},"published":"2026-04-24","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:15.186Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31539","references":[{"url":"https://git.kernel.org/stable/c/e811e60e1cc79923c4388146eb1fa26a7482731e"},{"url":"https://git.kernel.org/stable/c/f99996870222b598914a1f49d7375dc23752c237"},{"url":"https://git.kernel.org/stable/c/6e3c5052f9686192e178806e017b7377155f4bab"}],"tags":["cve.org"],"epss":0.00426,"epssPercentile":0.35414,"ingestedAt":"2026-10-16T17:24:46.660Z","slug":"CVE-2026-31539","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: smbdirect: introduce 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's because the peer might already consumed a credit,\nbut between receiving the incoming recv at the hardware\nand processing the completion in the 'recv_done' functions\nwe likely have a window where we grant credits, which\ndon't 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\n## Affected\n\n- `Linux >= 5fb9b459b3686e366640edd4e62805ef7b4de927 < e811e60e1cc79923c4388146eb1fa26a7482731e`\n- `Linux >= 5fb9b459b3686e366640edd4e62805ef7b4de927 < f99996870222b598914a1f49d7375dc23752c237`\n- `Linux >= 5fb9b459b3686e366640edd4e62805ef7b4de927 < 6e3c5052f9686192e178806e017b7377155f4bab`\n- `Linux 6.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}