In the Linux kernel, the following vulnerability has been resolved:

pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()

pwrseq_debugfs_seq_next() declares 'next' with __free(put_device),
which causes put_device() to be called on the returned pointer when
the variable goes out of scope. This results in a use-after-free
since the seq_file framework receives a pointer whose reference has
already been dropped.

Simply removing __free(put_device) would fix the UAF but would leak
the reference acquired by bus_find_next_device(), as stop() only
calls up_read(&pwrseq_sem) and never releases the device reference.

Fix this by making the reference counting consistent across all
seq_file callbacks, matching the standard pattern used by PCI and
SCSI:

- start(): use get_device() so it returns a referenced pointer.
- next(): explicitly put_device(curr) to release the previous
device's reference (no NULL check needed - the seq_file framework
only calls next() while the previous return was non-NULL).
- stop(): put_device(data) to release the last iterated device's
reference, with a NULL guard since stop() may be called with NULL
when start() returned NULL or next() reached end-of-sequence.
Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 12 Aug 2026 16:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Sun, 02 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Thu, 30 Jul 2026 05:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Wed, 29 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-911
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 27 Jul 2026 05:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Fri, 24 Jul 2026 18:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next() pwrseq_debugfs_seq_next() declares 'next' with __free(put_device), which causes put_device() to be called on the returned pointer when the variable goes out of scope. This results in a use-after-free since the seq_file framework receives a pointer whose reference has already been dropped. Simply removing __free(put_device) would fix the UAF but would leak the reference acquired by bus_find_next_device(), as stop() only calls up_read(&pwrseq_sem) and never releases the device reference. Fix this by making the reference counting consistent across all seq_file callbacks, matching the standard pattern used by PCI and SCSI: - start(): use get_device() so it returns a referenced pointer. - next(): explicitly put_device(curr) to release the previous device's reference (no NULL check needed - the seq_file framework only calls next() while the previous return was non-NULL). - stop(): put_device(data) to release the last iterated device's reference, with a NULL guard since stop() may be called with NULL when start() returned NULL or next() reached end-of-sequence.
Title pwrseq: core: fix use-after-free in pwrseq_debugfs_seq_next()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-05T12:40:17.105Z

Reserved: 2026-07-19T15:36:31.773Z

Link: CVE-2026-64251

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2026-07-24T16:16:54.713

Modified: 2026-08-12T15:53:38.763

Link: CVE-2026-64251

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-24T00:00:00Z

Links: CVE-2026-64251 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-13T11:00:12Z

Weaknesses