CVE-2022-49989

xen/privcmd: fix error exit of privcmd_ioctl_dm_op()

Published Jun 18, 2025 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

xen/privcmd: fix error exit of privcmd_ioctl_dm_op()

The error exit of privcmd_ioctl_dm_op() is calling unlock_pages()
potentially with pages being NULL, leading to a NULL dereference.

Additionally lock_pages() doesn't check for pin_user_pages_fast()
having been completely successful, resulting in potentially not
locking all pages into memory. This could result in sporadic failures
when using the related memory in user mode.

Fix all of that by calling unlock_pages() always with the real number
of pinned pages, which will be zero in case pages being NULL, and by
checking the number of pages pinned by pin_user_pages_fast() matching
the expected number of pages.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2022-55268 In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix error exit of privcmd_ioctl_dm_op() The error exit of privcmd_ioctl_dm_op() is calling unlock_pages() potentially with pages being NULL, leading to a NULL dereference. Additionally lock_pages() doesn't check for pin_user_pages_fast() having been completely successful, resulting in potentially not locking all pages into memory. This could result in sporadic failures when using the related memory in user mode. Fix all of that by calling unlock_pages() always with the real number of pinned pages, which will be zero in case pages being NULL, and by checking the number of pages pinned by pin_user_pages_fast() matching the expected number of pages.
History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*
Type Values Removed Values Added
Weaknesses CWE-476
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

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
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix error exit of privcmd_ioctl_dm_op() The error exit of privcmd_ioctl_dm_op() is calling unlock_pages() potentially with pages being NULL, leading to a NULL dereference. Additionally lock_pages() doesn't check for pin_user_pages_fast() having been completely successful, resulting in potentially not locking all pages into memory. This could result in sporadic failures when using the related memory in user mode. Fix all of that by calling unlock_pages() always with the real number of pinned pages, which will be zero in case pages being NULL, and by checking the number of pages pinned by pin_user_pages_fast() matching the expected number of pages.
Title xen/privcmd: fix error exit of privcmd_ioctl_dm_op()
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Nov 5, 2026, 8:00 PM
Reserved
Jun 18, 2025, 10:57 AM
Status
Analyzed
Published
Jun 18, 2025, 11:15 AM
Modified
Nov 5, 2026, 8:17 PM
Severity
Moderate
Public date
Jun 18, 2025, 12:00 AM