CVE-2023-53366

Kernel crash via polled I/O bio reuse

Published Sep 17, 2025 · Updated Sep 17, 2025

NULL pointer dereference in the Linux kernel block layer allows local users to crash the kernel through concurrent polled I/O. bio_poll reads bio->bi_bdev after another task sharing the poll queue can complete, cache, and reallocate the same bio, leaving that pointer NULL. Triggering the race requires two tasks using polled I/O with a shared poll queue and a preemption between completion and polling; the demonstrated consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel block layer allows local users to crash the kernel through concurrent polled I/O. bio_poll reads bio->bi_bdev after another task sharing the poll queue can complete, cache, and reallocate the same bio, leaving that pointer NULL. Triggering the race requires two tasks using polled I/O with a shared poll queue and a preemption between completion and polling; the demonstrated consequence is a kernel crash.

The record

CVE
CVE-2023-53366
Published
Sep 17, 2025
Updated
Sep 17, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.15
  2. Affected versionversion=be4d234d7aebbfe0c233bc20b9cdef7ab3408ff4 <0510d5e654d05053ed0e6309a9b42043ac9903ab
  3. Affected versionversion=be4d234d7aebbfe0c233bc20b9cdef7ab3408ff4 <1af0bdca03f367874da45d6cbe05fa05b90b1439
  4. Affected versionversion=be4d234d7aebbfe0c233bc20b9cdef7ab3408ff4 <310726c33ad76cebdee312dbfafc12c1b44bf977

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=be4d234d7aebbfe0c233bc20b9cdef7ab3408ff4 <0510d5e654d05053ed0e6309a9b42043ac9903ab; version=be4d234d7aebbfe0c233bc20b9cdef7ab3408ff4 <1af0bdca03f367874da45d6cbe05fa05b90b1439; version=be4d234d7aebbfe0c233bc20b9cdef7ab3408ff4 <310726c33ad76cebdee312dbfafc12c1b44bf977

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CVE.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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