CVE-2024-26674

CVE Details

Release Date:

2024-04-02

Description

In the Linux kernel, the following vulnerability has been resolved:\nx86/lib: Revert to _ASM_EXTABLE_UA() for {get,put}_user() fixups\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.\nmce: [Hardware Error]: CPU 296: Machine Check Exception: f Bank 1: bd80000000100134\nmce: [Hardware Error]: RIP 10: {__get_user_nocheck_4+0x6/0x20}\nmce: [Hardware Error]: TSC 411a93533ed ADDR 346a8730040 MISC 86\nmce: [Hardware Error]: PROCESSOR 0:a06d0 TIME 1706000767 SOCKET 1 APIC 211 microcode 80001490\nmce: [Hardware Error]: Run the above through 'mcelog --ascii'\nmce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel\nKernel panic - not syncing: Fatal local machine check\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.\nex_handler_uaccess() would warn if users gave a non-canonical addresses\n(with bit 63 clear) to {get, put}_user(), which was unexpected.\nTherefore, commit\nb19b74bc99b1 ('x86/mm: Rework address range check in get_user() and put_user()')\nreplaced _ASM_EXTABLE_UA() with _ASM_EXTABLE() for {get, put}_user()\nfixups. However, the new fixup type EX_TYPE_DEFAULT results in a panic.\nCommit\n6014bc27561f ('x86-64: make access_ok() independent of LAM')\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.\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[ bp: Massage commit message. ]

See more information about CVE-2024-26674 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	4.4	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	High	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14