{"id":"CVE-2025-21666","title":"vsock: prevent null-ptr-deref in vsock_*[has_data|has_space]","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: prevent null-ptr-deref in vsock_*[has_data|has_space]\n\nRecent reports have shown how we sometimes call vsock_*_has_data()\nwhen a vsock socket has been de-assigne…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"adp","vendor":"Linux","product":"Linux","affected":["Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < daeac89cdb03d30028186f5ff7dc26ec8fa843e7","Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < 9e5fed46ccd2c34c5fa5a9c8825ce4823fdc853e","Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < b52e50dd4fabd12944172bd486a4f4853b7f74dd","Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < bc9c49341f9728c31fe248c5fbba32d2e81a092b","Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < c23d1d4f8efefb72258e9cedce29de10d057f8ca","Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < 91751e248256efc111e52e15115840c35d85abaf","Linux 5.5"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2025-10-01T19:52:24.276957Z"},"published":"2025-01-31","updated":"2026-10-15","sourceUpdated":"2026-10-15T01:02:53.911Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-21666","references":[{"url":"https://git.kernel.org/stable/c/daeac89cdb03d30028186f5ff7dc26ec8fa843e7"},{"url":"https://git.kernel.org/stable/c/9e5fed46ccd2c34c5fa5a9c8825ce4823fdc853e"},{"url":"https://git.kernel.org/stable/c/b52e50dd4fabd12944172bd486a4f4853b7f74dd"},{"url":"https://git.kernel.org/stable/c/bc9c49341f9728c31fe248c5fbba32d2e81a092b"},{"url":"https://git.kernel.org/stable/c/c23d1d4f8efefb72258e9cedce29de10d057f8ca"},{"url":"https://git.kernel.org/stable/c/91751e248256efc111e52e15115840c35d85abaf"}],"tags":["cve.org"],"epss":0.00224,"epssPercentile":0.1292,"ingestedAt":"2026-10-15T04:46:37.354Z","slug":"CVE-2025-21666","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nvsock: prevent null-ptr-deref in vsock_*[has_data|has_space]\n\nRecent reports have shown how we sometimes call vsock_*_has_data()\nwhen a vsock socket has been de-assigned from a transport (see attached\nlinks), but we shouldn't.\n\nPrevious commits should have solved the real problems, but we may have\nmore in the future, so to avoid null-ptr-deref, we can return 0\n(no space, no data available) but with a warning.\n\nThis way the code should continue to run in a nearly consistent state\nand have a warning that allows us to debug future problems.\n\n## Affected\n\n- `Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < daeac89cdb03d30028186f5ff7dc26ec8fa843e7`\n- `Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < 9e5fed46ccd2c34c5fa5a9c8825ce4823fdc853e`\n- `Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < b52e50dd4fabd12944172bd486a4f4853b7f74dd`\n- `Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < bc9c49341f9728c31fe248c5fbba32d2e81a092b`\n- `Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < c23d1d4f8efefb72258e9cedce29de10d057f8ca`\n- `Linux >= c0cfa2d8a788fcf45df5bf4070ab2474c88d543a < 91751e248256efc111e52e15115840c35d85abaf`\n- `Linux 5.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}