Vulnerability-Lookup

FKIE_CVE-2026-23472

Vulnerability from fkie_nvd - Published: 2026-04-03 16:16 - Updated: 2026-05-26 14:26

Severity

5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: serial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN uart_write_room() and uart_write() behave inconsistently when xmit_buf is NULL (which happens for PORT_UNKNOWN ports that were never properly initialized): - uart_write_room() returns kfifo_avail() which can be > 0 - uart_write() checks xmit_buf and returns 0 if NULL This inconsistency causes an infinite loop in drivers that rely on tty_write_room() to determine if they can write: while (tty_write_room(tty) > 0) { written = tty->ops->write(...); // written is always 0, loop never exits } For example, caif_serial's handle_tx() enters an infinite loop when used with PORT_UNKNOWN serial ports, causing system hangs. Fix by making uart_write_room() also check xmit_buf and return 0 if it's NULL, consistent with uart_write(). Reproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/455ce986fa356ff43a43c0d363ba95fa152f21d5	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/bc70f2b36cf474d5cc8ecbcaf57f3e326fdec67c	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/efe85a557186b7fe915572ae93a8f3f78bfd9a22	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0

JSON

To clipboard

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      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nserial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN\n\nuart_write_room() and uart_write() behave inconsistently when\nxmit_buf is NULL (which happens for PORT_UNKNOWN ports that were\nnever properly initialized):\n\n- uart_write_room() returns kfifo_avail() which can be \u003e 0\n- uart_write() checks xmit_buf and returns 0 if NULL\n\nThis inconsistency causes an infinite loop in drivers that rely on\ntty_write_room() to determine if they can write:\n\n  while (tty_write_room(tty) \u003e 0) {\n      written = tty-\u003eops-\u003ewrite(...);\n      // written is always 0, loop never exits\n  }\n\nFor example, caif_serial\u0027s handle_tx() enters an infinite loop when\nused with PORT_UNKNOWN serial ports, causing system hangs.\n\nFix by making uart_write_room() also check xmit_buf and return 0 if\nit\u0027s NULL, consistent with uart_write().\n\nReproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13"
    }
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  "id": "CVE-2026-23472",
  "lastModified": "2026-05-26T14:26:13.110",
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          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
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  "published": "2026-04-03T16:16:34.977",
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          "value": "CWE-835"
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  ]
}

CVE-2026-23472 (GCVE-0-2026-23472)

Vulnerability from cvelistv5 – Published: 2026-04-03 15:15 – Updated: 2026-05-11 22:07

Title

serial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN

Summary

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/efe85a557186b7fe9…
https://git.kernel.org/stable/c/bc70f2b36cf474d5c…
https://git.kernel.org/stable/c/455ce986fa356ff43…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < efe85a557186b7fe915572ae93a8f3f78bfd9a22 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < bc70f2b36cf474d5cc8ecbcaf57f3e326fdec67c (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 455ce986fa356ff43a43c0d363ba95fa152f21d5 (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 6.18.20 , ≤ 6.18.* (semver) Unaffected: 6.19.10 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

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FKIE_CVE-2026-23472

CVE-2026-23472 (GCVE-0-2026-23472)

Tags

Sightings

Nomenclature