CVE-2021-46970

bus: mhi: pci_generic: Remove WQ_MEM_RECLAIM flag from state workqueue

Published Feb 27, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

bus: mhi: pci_generic: Remove WQ_MEM_RECLAIM flag from state workqueue

A recent change created a dedicated workqueue for the state-change work
with WQ_HIGHPRI (no strong reason for that) and WQ_MEM_RECLAIM flags,
but the state-change work (mhi_pm_st_worker) does not guarantee forward
progress under memory pressure, and will even wait on various memory
allocations when e.g. creating devices, loading firmware, etc... The
work is then not part of a memory reclaim path...

Moreover, this causes a warning in check_flush_dependency() since we end
up in code that flushes a non-reclaim workqueue:

[ 40.969601] workqueue: WQ_MEM_RECLAIM mhi_hiprio_wq:mhi_pm_st_worker [mhi] is flushing !WQ_MEM_RECLAIM events_highpri:flush_backlog
[ 40.969612] WARNING: CPU: 4 PID: 158 at kernel/workqueue.c:2607 check_flush_dependency+0x11c/0x140
[ 40.969733] Call Trace:
[ 40.969740] __flush_work+0x97/0x1d0
[ 40.969745] ? wake_up_process+0x15/0x20
[ 40.969749] ? insert_work+0x70/0x80
[ 40.969750] ? __queue_work+0x14a/0x3e0
[ 40.969753] flush_work+0x10/0x20
[ 40.969756] rollback_registered_many+0x1c9/0x510
[ 40.969759] unregister_netdevice_queue+0x94/0x120
[ 40.969761] unregister_netdev+0x1d/0x30
[ 40.969765] mhi_net_remove+0x1a/0x40 [mhi_net]
[ 40.969770] mhi_driver_remove+0x124/0x250 [mhi]
[ 40.969776] device_release_driver_internal+0xf0/0x1d0
[ 40.969778] device_release_driver+0x12/0x20
[ 40.969782] bus_remove_device+0xe1/0x150
[ 40.969786] device_del+0x17b/0x3e0
[ 40.969791] mhi_destroy_device+0x9a/0x100 [mhi]
[ 40.969796] ? mhi_unmap_single_use_bb+0x50/0x50 [mhi]
[ 40.969799] device_for_each_child+0x5e/0xa0
[ 40.969804] mhi_pm_st_worker+0x921/0xf50 [mhi]

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 2.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 1:45 PM
Reserved
Feb 27, 2024, 6:42 PM
Status
Analyzed
Published
Feb 27, 2024, 7:04 PM
Modified
Jun 17, 2026, 4:16 AM
Severity
Low
Public date
Feb 27, 2024, 12:00 AM