{"cve":"CVE-2024-40974","nvd":{"published":"2024-07-12T13:15:18.943","modified":"2026-08-04T11:19:11.263","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/pseries: Enforce hcall result buffer validity and size\n\nplpar_hcall(), plpar_hcall9(), and related functions expect callers to\nprovide valid result buffers of certain minimum size. Currently this\nis communicated only through comments in the code and the compiler has\nno idea.\n\nFor example, if I write a bug like this:\n\n  long retbuf[PLPAR_HCALL_BUFSIZE]; // should be PLPAR_HCALL9_BUFSIZE\n  plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, ...);\n\nThis compiles with no diagnostics emitted, but likely results in stack\ncorruption at runtime when plpar_hcall9() stores results past the end\nof the array. (To be clear this is a contrived example and I have not\nfound a real instance yet.)\n\nTo make this class of error less likely, we can use explicitly-sized\narray parameters instead of pointers in the declarations for the hcall\nAPIs. When compiled with -Warray-bounds[1], the code above now\nprovokes a diagnostic like this:\n\nerror: array argument is too small;\nis of size 32, callee requires at least 72 [-Werror,-Warray-bounds]\n   60 |                 plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf,\n      |                 ^                                   ~~~~~~\n\n[1] Enabled for LLVM builds but not GCC for now. See commit\n    0da6e5fd6c37 (\"gcc: disable '-Warray-bounds' for gcc-13 too\") and\n    related changes.","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/19c166ee42cf16d8b156a6cb4544122d9a65d3ca","https://git.kernel.org/stable/c/262e942ff5a839b9e4f3302a8987928b0c8b8a2d","https://git.kernel.org/stable/c/3ad0034910a57aa88ed9976b1431b7b8c84e0048","https://git.kernel.org/stable/c/8aa11aa001576bf3b00dcb8559564ad7a3113588","https://git.kernel.org/stable/c/a8c988d752b3d98d5cc1e3929c519a55ef55426c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:52:42.518321223+00:00"},"epss":{"cve":"CVE-2024-40974","score":0.00302,"percentile":0.23026,"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."]}