CVE-2025-38037
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
vxlan: Annotate FDB data races
The 'used' and 'updated' fields in the FDB entry structure can be accessed concurrently by multiple threads, leading to reports such as [1]. Can be reproduced using [2].
Suppress these reports by annotating these accesses using READ_ONCE() / WRITE_ONCE().
value changed: 0x00000000fffbac6e -> 0x00000000fffbac6f
[2] #!/bin/bash
set +H echo whitelist > /sys/kernel/debug/kcsan echo !vxlan_xmit > /sys/kernel/debug/kcsan
ip link add name vx0 up type vxlan id 10010 dstport 4789 local 192.0.2.1 bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 198.51.100.1 taskset -c 0 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q & taskset -c 2 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &
Detalles técnicos trazas, registros y código del informe original
[1] BUG: KCSAN: data-race in vxlan_xmit / vxlan_xmit write to 0xffff942604d263a8 of 8 bytes by task 286 on cpu 0: vxlan_xmit+0xb29/0x2380 dev_hard_start_xmit+0x84/0x2f0 __dev_queue_xmit+0x45a/0x1650 packet_xmit+0x100/0x150 packet_sendmsg+0x2114/0x2ac0 __sys_sendto+0x318/0x330 __x64_sys_sendto+0x76/0x90 x64_sys_call+0x14e8/0x1c00 do_syscall_64+0x9e/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff942604d263a8 of 8 bytes by task 287 on cpu 2: vxlan_xmit+0xadf/0x2380 dev_hard_start_xmit+0x84/0x2f0 __dev_queue_xmit+0x45a/0x1650 packet_xmit+0x100/0x150 packet_sendmsg+0x2114/0x2ac0 __sys_sendto+0x318/0x330 __x64_sys_sendto+0x76/0x90 x64_sys_call+0x14e8/0x1c00 do_syscall_64+0x9e/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported by Kernel Concurrency Sanitizer on: CPU: 2 UID: 0 PID: 287 Comm: mausezahn Not tainted 6.13.0-rc7-01544-gb4b270f11a02 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.22%
- Percentil entre todas las CVEs puntuadas: 11
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (2)
CWE
- NVD-CWE-noinfo
Referencias
- https://git.kernel.org/stable/c/02a33b1035a307453a1da6ce0a1bf3676be287d7
- https://git.kernel.org/stable/c/13cba3f837903f7184d6e9b6137d5165ffe82a8f
- https://git.kernel.org/stable/c/4eceb7eae6ea7c950384c34e6dbbe872c981935f
- https://git.kernel.org/stable/c/784b78295a3a58bf052339dd669e6e03710220d3
- https://git.kernel.org/stable/c/87d076987a9ba106c83412fcd113656f71af05a1
- https://git.kernel.org/stable/c/a6644aeb8ddf196dec5f8e782293c36f065df4d7
- https://git.kernel.org/stable/c/e033da39fc6abbddab6c29624acef80757f273fa
- https://git.kernel.org/stable/c/f6205f8215f12a96518ac9469ff76294ae7bd612
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
JSON original (NVD)
Mostrar
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"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"
},
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{
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{
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{
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"versionType": "semver",
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},
{
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"version": "6.14.9",
"versionType": "semver",
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{
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"version": "6.15",
"versionType": "original_commit_for_fix",
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"programFiles": [
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],
"defaultStatus": "affected"
}
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],
"published": "2025-06-18T10:15:36.030",
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},
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"tags": [
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],
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},
{
"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html",
"tags": [
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],
"source": "af854a3a-2127-422b-91ae-364da2661108"
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],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: Annotate FDB data races\n\nThe 'used' and 'updated' fields in the FDB entry structure can be\naccessed concurrently by multiple threads, leading to reports such as\n[1]. Can be reproduced using [2].\n\nSuppress these reports by annotating these accesses using\nREAD_ONCE() / WRITE_ONCE().\n\n[1]\nBUG: KCSAN: data-race in vxlan_xmit / vxlan_xmit\n\nwrite to 0xffff942604d263a8 of 8 bytes by task 286 on cpu 0:\n vxlan_xmit+0xb29/0x2380\n dev_hard_start_xmit+0x84/0x2f0\n __dev_queue_xmit+0x45a/0x1650\n packet_xmit+0x100/0x150\n packet_sendmsg+0x2114/0x2ac0\n __sys_sendto+0x318/0x330\n __x64_sys_sendto+0x76/0x90\n x64_sys_call+0x14e8/0x1c00\n do_syscall_64+0x9e/0x1a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nread to 0xffff942604d263a8 of 8 bytes by task 287 on cpu 2:\n vxlan_xmit+0xadf/0x2380\n dev_hard_start_xmit+0x84/0x2f0\n __dev_queue_xmit+0x45a/0x1650\n packet_xmit+0x100/0x150\n packet_sendmsg+0x2114/0x2ac0\n __sys_sendto+0x318/0x330\n __x64_sys_sendto+0x76/0x90\n x64_sys_call+0x14e8/0x1c00\n do_syscall_64+0x9e/0x1a0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nvalue changed: 0x00000000fffbac6e -> 0x00000000fffbac6f\n\nReported by Kernel Concurrency Sanitizer on:\nCPU: 2 UID: 0 PID: 287 Comm: mausezahn Not tainted 6.13.0-rc7-01544-gb4b270f11a02 #5\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014\n\n[2]\n #!/bin/bash\n\n set +H\n echo whitelist > /sys/kernel/debug/kcsan\n echo !vxlan_xmit > /sys/kernel/debug/kcsan\n\n ip link add name vx0 up type vxlan id 10010 dstport 4789 local 192.0.2.1\n bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 198.51.100.1\n taskset -c 0 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &\n taskset -c 2 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &"
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: vxlan: Anotación de ejecuciones de datos FDB. Múltiples subprocesos pueden acceder simultáneamente a los campos \"usado\" y \"actualizado\" de la estructura de entrada FDB, lo que genera informes como [1]. Se puede reproducir con [2]. Para suprimir estos informes, anote estos accesos con READ_ONCE() / WRITE_ONCE(). [1] ERROR: KCSAN: ejecución de datos en vxlan_xmit / vxlan_xmit escribe en 0xffff942604d263a8 de 8 bytes por la tarea 286 en la CPU 0: vxlan_xmit+0xb29/0x2380 dev_hard_start_xmit+0x84/0x2f0 __dev_queue_xmit+0x45a/0x1650 packet_xmit+0x100/0x150 packet_sendmsg+0x2114/0x2ac0 __sys_sendto+0x318/0x330 __x64_sys_sendto+0x76/0x90 x64_sys_call+0x14e8/0x1c00 do_syscall_64+0x9e/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f lectura a 0xffff942604d263a8 de 8 bytes por la tarea 287 en la CPU 2: vxlan_xmit+0xadf/0x2380 dev_hard_start_xmit+0x84/0x2f0 __dev_queue_xmit+0x45a/0x1650 packet_xmit+0x100/0x150 packet_sendmsg+0x2114/0x2ac0 __sys_sendto+0x318/0x330 __x64_sys_sendto+0x76/0x90 x64_sys_call+0x14e8/0x1c00 do_syscall_64+0x9e/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f valor cambiado: 0x00000000fffbac6e -> 0x00000000fffbac6f Informado por Kernel Concurrency Sanitizer en: CPU: 2 UID: 0 PID: 287 Comm: mausezahn No contaminado 6.13.0-rc7-01544-gb4b270f11a02 #5 Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 01/04/2014 [2] #!/bin/bash set +H echo whitelist > /sys/kernel/debug/kcsan echo !vxlan_xmit > /sys/kernel/debug/kcsan ip enlace agregar nombre vx0 activo tipo vxlan id 10010 dstport 4789 local 192.0.2.1 puente fdb agregar 00:11:22:33:44:55 dev vx0 self static dst 198.51.100.1 conjunto de tareas -c 0 mausezahn vx0 -a propio -b 00:11:22:33:44:55 -c 0 -q & conjunto de tareas -c 2 mausezahn vx0 -a propio -b 00:11:22:33:44:55 -c 0 -q &"
}
],
"lastModified": "2026-06-17T09:15:55.653",
"configurations": [
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