{"cve":"CVE-2021-47496","nvd":{"published":"2024-05-22T09:15:11.447","modified":"2026-08-04T10:17:05.910","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: Fix flipped sign in tls_err_abort() calls\n\nsk->sk_err appears to expect a positive value, a convention that ktls\ndoesn't always follow and that leads to memory corruption in other code.\nFor instance,\n\n    [kworker]\n    tls_encrypt_done(..., err=<negative error from crypto request>)\n      tls_err_abort(.., err)\n        sk->sk_err = err;\n\n    [task]\n    splice_from_pipe_feed\n      ...\n        tls_sw_do_sendpage\n          if (sk->sk_err) {\n            ret = -sk->sk_err;  // ret is positive\n\n    splice_from_pipe_feed (continued)\n      ret = actor(...)  // ret is still positive and interpreted as bytes\n                        // written, resulting in underflow of buf->len and\n                        // sd->len, leading to huge buf->offset and bogus\n                        // addresses computed in later calls to actor()\n\nFix all tls_err_abort() callers to pass a negative error code\nconsistently and centralize the error-prone sign flip there, throwing in\na warning to catch future misuse and uninlining the function so it\nreally does only warn once.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-787"],"references":["https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105","https://git.kernel.org/stable/c/e0cfd5159f314d6b304d030363650b06a2299cbb","https://git.kernel.org/stable/c/e41473543f75f7dbc5d605007e6f883f1bd13b9a","https://git.kernel.org/stable/c/f3dec7e7ace38224f82cf83f0049159d067c2e19","https://git.kernel.org/stable/c/da353fac65fede6b8b4cfe207f0d9408e3121105"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47496","score":0.00483,"percentile":0.41687,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}