{"id":"CVE-2024-40974","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-40974","generatedAt":"2026-10-28T05:58:27.372Z","title":"In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries: Enforce hcall result buffer validity and size plpar_hcall(), plpar_hcall9(), and related functions expect callers to provide valid result buffers of certain minimum size.","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.","published":"2024-07-12T13:15:19.000Z","lastModified":"2026-08-04T11:19:11.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-787"],"affected":["linux/linux kernel"],"epss":{"score":0.00302,"percentile":0.22841,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/19c166ee42cf16d8b156a6cb4544122d9a65d3ca","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/262e942ff5a839b9e4f3302a8987928b0c8b8a2d","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3ad0034910a57aa88ed9976b1431b7b8c84e0048","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8aa11aa001576bf3b00dcb8559564ad7a3113588","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a8c988d752b3d98d5cc1e3929c519a55ef55426c","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aa6107dcc4ce9a3451f2d729204713783b657257","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/acf2b80c31c37acab040baa3cf5f19fbd5140b18","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ff2e185cf73df480ec69675936c4ee75a445c3e4","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/19c166ee42cf16d8b156a6cb4544122d9a65d3ca","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/262e942ff5a839b9e4f3302a8987928b0c8b8a2d","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/3ad0034910a57aa88ed9976b1431b7b8c84e0048","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/8aa11aa001576bf3b00dcb8559564ad7a3113588","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a8c988d752b3d98d5cc1e3929c519a55ef55426c","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/aa6107dcc4ce9a3451f2d729204713783b657257","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/acf2b80c31c37acab040baa3cf5f19fbd5140b18","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/ff2e185cf73df480ec69675936c4ee75a445c3e4","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-40974","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}