{"cve":"CVE-2017-1000255","nvd":{"published":"2017-10-30T20:29:00.230","modified":"2026-06-17T00:59:00.167","status":"Modified","description":"On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from the signal frame* as the kernel stack pointer. As part of the exception entry the content of the signal frame is written to the kernel stack, allowing an attacker to overwrite arbitrary locations with arbitrary values. The exception handling does produce an oops, and a panic if panic_on_oops=1, but only after kernel memory has been over written. This flaw was introduced in commit: \"5d176f751ee3 (powerpc: tm: Enable transactional memory (TM) lazily for userspace)\" which was merged upstream into v4.9-rc1. Please note that kernels built with CONFIG_PPC_TRANSACTIONAL_MEM=n are not vulnerable.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","score":5.5},"cwes":["CWE-787"],"references":["http://www.securityfocus.com/bid/101264","https://access.redhat.com/errata/RHSA-2018:0654","https://access.redhat.com/security/cve/CVE-2017-1000255","http://www.securityfocus.com/bid/101264","https://access.redhat.com/errata/RHSA-2018:0654"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T20:47:01.408438353+00:00"},"epss":{"cve":"CVE-2017-1000255","score":0.00382,"percentile":0.32193,"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."]}