{"cve":"CVE-2023-52504","nvd":{"published":"2024-03-02T22:15:47.300","modified":"2026-06-17T06:42:52.927","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/alternatives: Disable KASAN in apply_alternatives()\n\nFei has reported that KASAN triggers during apply_alternatives() on\na 5-level paging machine:\n\n\tBUG: KASAN: out-of-bounds in rcu_is_watching()\n\tRead of size 4 at addr ff110003ee6419a0 by task swapper/0/0\n\t...\n\t__asan_load4()\n\trcu_is_watching()\n\ttrace_hardirqs_on()\n\ttext_poke_early()\n\tapply_alternatives()\n\t...\n\nOn machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57)\ngets patched. It includes KASAN code, where KASAN_SHADOW_START depends on\n__VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled().\n\nKASAN gets confused when apply_alternatives() patches the\nKASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START\nstatic, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue.\n\nFix it for real by disabling KASAN while the kernel is patching alternatives.\n\n[ mingo: updated the changelog ]","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:N/A:H","score":7.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/3719d3c36aa853d5a2401af9f8d6b116c91ad5ae","https://git.kernel.org/stable/c/3770c38cd6a60494da29ac2da73ff8156440a2d1","https://git.kernel.org/stable/c/5b784489c8158518bf7a466bb3cc045b0fb66b4b","https://git.kernel.org/stable/c/6788b10620ca6e98575d1e06e72a8974aad7657e","https://git.kernel.org/stable/c/cd287cc208dfe6bd6da98e7f88e723209242c9b4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:46:54.846886191+00:00"},"epss":{"cve":"CVE-2023-52504","score":0.00278,"percentile":0.20248,"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."]}