{"cve":"CVE-2024-26674","nvd":{"published":"2024-04-02T07:15:44.033","modified":"2026-06-17T07:18:03.893","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/lib: Revert to _ASM_EXTABLE_UA() for {get,put}_user() fixups\n\nDuring memory error injection test on kernels >= v6.4, the kernel panics\nlike below. However, this issue couldn't be reproduced on kernels <= v6.3.\n\n  mce: [Hardware Error]: CPU 296: Machine Check Exception: f Bank 1: bd80000000100134\n  mce: [Hardware Error]: RIP 10:<ffffffff821b9776> {__get_user_nocheck_4+0x6/0x20}\n  mce: [Hardware Error]: TSC 411a93533ed ADDR 346a8730040 MISC 86\n  mce: [Hardware Error]: PROCESSOR 0:a06d0 TIME 1706000767 SOCKET 1 APIC 211 microcode 80001490\n  mce: [Hardware Error]: Run the above through 'mcelog --ascii'\n  mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel\n  Kernel panic - not syncing: Fatal local machine check\n\nThe MCA code can recover from an in-kernel #MC if the fixup type is\nEX_TYPE_UACCESS, explicitly indicating that the kernel is attempting to\naccess userspace memory. However, if the fixup type is EX_TYPE_DEFAULT\nthe only thing that is raised for an in-kernel #MC is a panic.\n\nex_handler_uaccess() would warn if users gave a non-canonical addresses\n(with bit 63 clear) to {get, put}_user(), which was unexpected.\n\nTherefore, commit\n\n  b19b74bc99b1 (\"x86/mm: Rework address range check in get_user() and put_user()\")\n\nreplaced _ASM_EXTABLE_UA() with _ASM_EXTABLE() for {get, put}_user()\nfixups. However, the new fixup type EX_TYPE_DEFAULT results in a panic.\n\nCommit\n\n  6014bc27561f (\"x86-64: make access_ok() independent of LAM\")\n\nadded the check gp_fault_address_ok() right before the WARN_ONCE() in\nex_handler_uaccess() to not warn about non-canonical user addresses due\nto LAM.\n\nWith that in place, revert back to _ASM_EXTABLE_UA() for {get,put}_user()\nexception fixups in order to be able to handle in-kernel MCEs correctly\nagain.\n\n  [ bp: Massage commit message. ]","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-787"],"references":["https://git.kernel.org/stable/c/2aed1b6c33afd8599d01c6532bbecb829480a674","https://git.kernel.org/stable/c/2da241c5ed78d0978228a1150735539fe1a60eca","https://git.kernel.org/stable/c/8eed4e00a370b37b4e5985ed983dccedd555ea9d","https://git.kernel.org/stable/c/2aed1b6c33afd8599d01c6532bbecb829480a674","https://git.kernel.org/stable/c/2da241c5ed78d0978228a1150735539fe1a60eca"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:47:51.568503435+00:00"},"epss":{"cve":"CVE-2024-26674","score":0.00264,"percentile":0.18255,"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."]}