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Vulnerability · CVE-2023-53143

In the Linux kernel, the following vulnerability has been resolved: ext4: fix another off-by-one fsmap error on 1k block filesystems Apparently syzbot figured out that issuing this

Published May 2, 2025 · corrected/updated May 11, 2026 · Linux Linux · evidence confidence high

In the Linux kernel, the following vulnerability has been resolved: ext4: fix another off-by-one fsmap error on 1k block filesystems Apparently syzbot figured out that issuing this FSMAP call: struct fsmap_head cmd = { .fmh_count = ...; .fmh_keys = { { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, }, ... }; ret = ioctl(fd, FS_IOC_GETFSMAP, &cmd); Produces this crash if the underlying filesystem is a 1k-block ext4 filesystem: kernel BUG at fs/ext4/ext4.h:3331! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 3 PID: 3227965 Comm: xfs_io Taint

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2023-53143 is a none public vulnerability record for Linux Linux. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Linux Linux is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: Linux Linux 4a4956249dac0b9b0027949907bff0cd1a9b57fa <a70b49dc7eee5dbe3775a650ce598e3557ff5475 (4a4956249dac0b9b0027949907bff0cd1a9b57fa <a70b49dc7eee5dbe3775a650ce598e3557ff5475). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 0.0, EPSS 19.0%. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: euvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 2, 2025 · EUVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: ext4: fix another off-by-one fsmap error on 1k block filesystems Apparently syzbot figured out that issuing this FSMAP call: struct fsmap_head cmd = { .fmh_count = ...; .fmh_keys = { { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, }, ... }; ret = ioctl(fd, FS_IOC_GETFSMAP

  2. May 11, 2026 · EUVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: ext4: fix another off-by-one fsmap error on 1k block filesystems Apparently syzbot figured out that issuing this FSMAP call: struct fsmap_head cmd = { .fmh_count = ...; .fmh_keys = { { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, }, ... }; ret = ioctl(fd, FS_IOC_GETFSMAP

Affected

  • vendor Linux Linux 4a4956249dac0b9b0027949907bff0cd1a9b57fa <a70b49dc7eee5dbe3775a650ce598e3557ff54754a4956249dac0b9b0027949907bff0cd1a9b57fa <a70b49dc7eee5dbe3775a650ce598e3557ff5475

Sources

  • EUVDVulnerability recordEUVD-2025-13126

    In the Linux kernel, the following vulnerability has been resolved: ext4: fix another off-by-one fsmap error on 1k block filesystems Apparently syzbot figured out that issuing this FSMAP call: struct fsmap_head cmd = { .fmh_count = ...; .fmh_keys = { { .fmr_device = /* ext4 dev *

    euvd.enisa.europa.eu

References