CVE-2025-21820

{"id": "CVE-2025-21820", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-02-27T20:16:04.520", "references": [{"url": "https://git.kernel.org/stable/c/4410dba9807a17a93f649a9f5870ceaf30a675a3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9b88a7c4584ba67267a051069b8abe44fc9595b2", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b06f388994500297bb91be60ffaf6825ecfd2afe", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/de5bd24197bd9ee37ec1e379a3d882bbd15c5065", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e22a97700901ba5e8bf8db68056a0d50f9440cae", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html", "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-667"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: xilinx_uartps: split sysrq handling\n\nlockdep detects the following circular locking dependency:\n\nCPU 0 CPU 1\n========================== ============================\ncdns_uart_isr() printk()\n uart_port_lock(port) console_lock()\n\t\t\t cdns_uart_console_write()\n if (!port->sysrq)\n uart_port_lock(port)\n uart_handle_break()\n port->sysrq = ...\n uart_handle_sysrq_char()\n printk()\n console_lock()\n\nThe fixed commit attempts to avoid this situation by only taking the\nport lock in cdns_uart_console_write if port->sysrq unset. However, if\n(as shown above) cdns_uart_console_write runs before port->sysrq is set,\nthen it will try to take the port lock anyway. This may result in a\ndeadlock.\n\nFix this by splitting sysrq handling into two parts. We use the prepare\nhelper under the port lock and defer handling until we release the lock."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tty: xilinx_uartps: la gesti\u00f3n dividido de sysrq lockdep detecta la siguiente dependencia de bloqueo circular: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. Sin embargo, si (como se muestra arriba) cdns_uart_console_write se ejecuta antes de que port->sysrq est\u00e9 configurado, entonces intentar\u00e1 tomar el bloqueo del puerto de todos modos. Esto puede resultar en un bloqueo. Solucione esto dividiendo la gesti\u00f3n de sysrq en dos partes. Usamos el asistente de preparaci\u00f3n bajo el bloqueo del puerto y posponemos la gesti\u00f3n hasta que liberemos el bloqueo."}], "lastModified": "2025-11-03T21:19:12.597", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "931829B0-EF08-4EA8-A30B-4A6456FC70A0", "versionEndExcluding": "6.1.129", "versionStartIncluding": "4.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0C58261F-EDFB-4A12-8CCD-F12101482030", "versionEndExcluding": "6.6.78", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "033BB7EE-C9A2-45EA-BAC9-87BB9D951BCD", "versionEndExcluding": "6.12.14", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0E92CEE3-1FC3-4AFC-A513-DEDBA7414F00", "versionEndExcluding": "6.13.3", "versionStartIncluding": "6.13"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}