Common Weakness Enumeration

CWE-835

Allowed

Loop with Unreachable Exit Condition ('Infinite Loop')

Abstraction: Base · Status: Incomplete

API response cwe.mitre.org

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

1133 vulnerabilities reference this CWE, most recent first.

GHSA-XX77-8CP4-RX22

Vulnerability from github – Published: 2026-04-03 18:31 – Updated: 2026-05-26 15:32
VLAI
Details

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

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-23472"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-03T16:16:34Z",
    "severity": "MODERATE"
  },
  "details": "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",
  "id": "GHSA-xx77-8cp4-rx22",
  "modified": "2026-05-26T15:32:07Z",
  "published": "2026-04-03T18:31:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23472"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/455ce986fa356ff43a43c0d363ba95fa152f21d5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bc70f2b36cf474d5cc8ecbcaf57f3e326fdec67c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/efe85a557186b7fe915572ae93a8f3f78bfd9a22"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-XXQF-CF9X-9RWQ

Vulnerability from github – Published: 2022-05-24 17:08 – Updated: 2022-05-24 17:08
VLAI
Details

lib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated by the unauthenticated triggering of a submission-login infinite loop.

Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2020-7046"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2020-02-12T17:15:00Z",
    "severity": "HIGH"
  },
  "details": "lib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated by the unauthenticated triggering of a submission-login infinite loop.",
  "id": "GHSA-xxqf-cf9x-9rwq",
  "modified": "2022-05-24T17:08:50Z",
  "published": "2022-05-24T17:08:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-7046"
    },
    {
      "type": "WEB",
      "url": "https://dovecot.org/pipermail/dovecot-news/2020-February/000431.html"
    },
    {
      "type": "WEB",
      "url": "https://dovecot.org/security"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6XYT55WH372BJOXCJRKBDIFGBMPVOIDT"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NJXHOUT3FH2DJNMACSX4GHPP4MUV4UKA"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2020/02/12/1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-XXQH-R526-FMP5

Vulnerability from github – Published: 2022-05-13 01:23 – Updated: 2025-04-20 03:38
VLAI
Details

The cr_parser_parse_selector_core function in cr-parser.c in libcroco 0.6.12 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a crafted CSS file.

Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2017-8871"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2017-06-12T06:29:00Z",
    "severity": "HIGH"
  },
  "details": "The cr_parser_parse_selector_core function in cr-parser.c in libcroco 0.6.12 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a crafted CSS file.",
  "id": "GHSA-xxqh-r526-fmp5",
  "modified": "2025-04-20T03:38:48Z",
  "published": "2022-05-13T01:23:13Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2017-8871"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.gnome.org/show_bug.cgi?id=782649"
    },
    {
      "type": "WEB",
      "url": "https://www.exploit-db.com/exploits/42147"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00043.html"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2020/08/13/3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

No mitigation information available for this CWE.

No CAPEC attack patterns related to this CWE.

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