CVE-2024-49866

CVE Details

Release Date:

2024-10-21

Description

In the Linux kernel, the following vulnerability has been resolved:\ntracing/timerlat: Fix a race during cpuhp processing\nThere is another found exception that the 'timerlat/1' thread was\nscheduled on CPU0, and lead to timer corruption finally:\n```\nODEBUG: init active (active state 0) object: ffff888237c2e108 object type: hrtimer hint: timerlat_irq+0x0/0x220\nWARNING: CPU: 0 PID: 426 at lib/debugobjects.c:518 debug_print_object+0x7d/0xb0\nModules linked in:\nCPU: 0 UID: 0 PID: 426 Comm: timerlat/1 Not tainted 6.11.0-rc7+ #45\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014\nRIP: 0010:debug_print_object+0x7d/0xb0\n...\nCall Trace:\n\n? __warn+0x7c/0x110\n? debug_print_object+0x7d/0xb0\n? report_bug+0xf1/0x1d0\n? prb_read_valid+0x17/0x20\n? handle_bug+0x3f/0x70\n? exc_invalid_op+0x13/0x60\n? asm_exc_invalid_op+0x16/0x20\n? debug_print_object+0x7d/0xb0\n? debug_print_object+0x7d/0xb0\n? __pfx_timerlat_irq+0x10/0x10\n__debug_object_init+0x110/0x150\nhrtimer_init+0x1d/0x60\ntimerlat_main+0xab/0x2d0\n? __pfx_timerlat_main+0x10/0x10\nkthread+0xb7/0xe0\n? __pfx_kthread+0x10/0x10\nret_from_fork+0x2d/0x40\n? __pfx_kthread+0x10/0x10\nret_from_fork_asm+0x1a/0x30\n\n```\nAfter tracing the scheduling event, it was discovered that the migration\nof the 'timerlat/1' thread was performed during thread creation. Further\nanalysis confirmed that it is because the CPU online processing for\nosnoise is implemented through workers, which is asynchronous with the\noffline processing. When the worker was scheduled to create a thread, the\nCPU may has already been removed from the cpu_online_mask during the offline\nprocess, resulting in the inability to select the right CPU:\nT1 | T2\n[CPUHP_ONLINE] | cpu_device_down()\nosnoise_hotplug_workfn() |\n| cpus_write_lock()\n| takedown_cpu(1)\n| cpus_write_unlock()\n[CPUHP_OFFLINE] |\ncpus_read_lock() |\nstart_kthread(1) |\ncpus_read_unlock() |\nTo fix this, skip online processing if the CPU is already offline.

See more information about CVE-2024-49866 from MITRE CVE dictionary and NIST NVD

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

CVSS v3 metrics

Base Score:	4.1
Vector String:	CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	High
Privileges Required:	High
User Interaction:	None
Scope:	Unchanged
Confidentiality:	None
Integrity:	None
Availability:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (kernel-uek)	ELSA-2024-12887	2024-12-18
Oracle Linux version 9 (kernel-uek)	ELSA-2024-12887	2024-12-18