FKIE_CVE-2025-39773
Vulnerability from fkie_nvd - Published: 2025-09-11 17:15 - Updated: 2026-10-19 21:10
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: fix soft lockup in br_multicast_query_expired()
When set multicast_query_interval to a large value, the local variable
'time' in br_multicast_send_query() may overflow. If the time is smaller
than jiffies, the timer will expire immediately, and then call mod_timer()
again, which creates a loop and may trigger the following soft lockup
issue.
watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66]
CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none)
Call Trace:
<IRQ>
__netdev_alloc_skb+0x2e/0x3a0
br_ip6_multicast_alloc_query+0x212/0x1b70
__br_multicast_send_query+0x376/0xac0
br_multicast_send_query+0x299/0x510
br_multicast_query_expired.constprop.0+0x16d/0x1b0
call_timer_fn+0x3b/0x2a0
__run_timers+0x619/0x950
run_timer_softirq+0x11c/0x220
handle_softirqs+0x18e/0x560
__irq_exit_rcu+0x158/0x1a0
sysvec_apic_timer_interrupt+0x76/0x90
</IRQ>
This issue can be reproduced with:
ip link add br0 type bridge
echo 1 > /sys/class/net/br0/bridge/multicast_querier
echo 0xffffffffffffffff >
/sys/class/net/br0/bridge/multicast_query_interval
ip link set dev br0 up
The multicast_startup_query_interval can also cause this issue. Similar to
the commit 99b40610956a ("net: bridge: mcast: add and enforce query
interval minimum"), add check for the query interval maximum to fix this
issue.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | 6.17 | |
| linux | linux_kernel | 6.17 | |
| debian | debian_linux | 11.0 |
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}
]
}
],
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},
{
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{
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"product": "SIMATIC CN 4100",
"vendor": "Siemens",
"versions": [
{
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"status": "affected",
"version": "0",
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}
]
},
{
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"vendor": "Siemens",
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{
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{
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{
"defaultStatus": "unknown",
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"vendor": "Siemens",
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{
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{
"defaultStatus": "unknown",
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"vendor": "Siemens",
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{
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"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.5",
"versionType": "custom"
}
]
},
{
"defaultStatus": "unknown",
"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
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{
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{
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"vendor": "Siemens",
"versions": [
{
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"status": "affected",
"version": "V3.1.7",
"versionType": "custom"
}
]
}
],
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
],
"configurations": [
{
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"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: fix soft lockup in br_multicast_query_expired()\n\nWhen set multicast_query_interval to a large value, the local variable\n\u0027time\u0027 in br_multicast_send_query() may overflow. If the time is smaller\nthan jiffies, the timer will expire immediately, and then call mod_timer()\nagain, which creates a loop and may trigger the following soft lockup\nissue.\n\n watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66]\n CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none)\n Call Trace:\n \u003cIRQ\u003e\n __netdev_alloc_skb+0x2e/0x3a0\n br_ip6_multicast_alloc_query+0x212/0x1b70\n __br_multicast_send_query+0x376/0xac0\n br_multicast_send_query+0x299/0x510\n br_multicast_query_expired.constprop.0+0x16d/0x1b0\n call_timer_fn+0x3b/0x2a0\n __run_timers+0x619/0x950\n run_timer_softirq+0x11c/0x220\n handle_softirqs+0x18e/0x560\n __irq_exit_rcu+0x158/0x1a0\n sysvec_apic_timer_interrupt+0x76/0x90\n \u003c/IRQ\u003e\n\nThis issue can be reproduced with:\n ip link add br0 type bridge\n echo 1 \u003e /sys/class/net/br0/bridge/multicast_querier\n echo 0xffffffffffffffff \u003e\n \t/sys/class/net/br0/bridge/multicast_query_interval\n ip link set dev br0 up\n\nThe multicast_startup_query_interval can also cause this issue. Similar to\nthe commit 99b40610956a (\"net: bridge: mcast: add and enforce query\ninterval minimum\"), add check for the query interval maximum to fix this\nissue."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: bridge: corregir soft lockup en br_multicast_query_expired()\n\nCuando se establece multicast_query_interval a un valor grande, la variable local \u0027time\u0027 en br_multicast_send_query() puede desbordarse. Si el tiempo es menor que jiffies, el temporizador expirar\u00e1 inmediatamente, y luego llamar\u00e1 a mod_timer() de nuevo, lo que crea un bucle y puede desencadenar el siguiente problema de soft lockup.\n\n watchdog: BUG: soft lockup - CPU#1 atascada durante 221s! [rb_consumer:66]\n CPU: 1 UID: 0 PID: 66 Comm: rb_consumer No contaminado 6.16.0+ #259 PREEMPT(none)\n Traza de Llamada:\n \u003cIRQ\u003e\n __netdev_alloc_skb+0x2e/0x3a0\n br_ip6_multicast_alloc_query+0x212/0x1b70\n __br_multicast_send_query+0x376/0xac0\n br_multicast_send_query+0x299/0x510\n br_multicast_query_expired.constprop.0+0x16d/0x1b0\n call_timer_fn+0x3b/0x2a0\n __run_timers+0x619/0x950\n run_timer_softirq+0x11c/0x220\n handle_softirqs+0x18e/0x560\n __irq_exit_rcu+0x158/0x1a0\n sysvec_apic_timer_interrupt+0x76/0x90\n \u003c/IRQ\u003e\n\nEste problema puede reproducirse con:\n ip link add br0 type bridge\n echo 1 \u003e /sys/class/net/br0/bridge/multicast_querier\n echo 0xffffffffffffffff \u003e\n \t/sys/class/net/br0/bridge/multicast_query_interval\n ip link set dev br0 up\n\nEl multicast_startup_query_interval tambi\u00e9n puede causar este problema. Similar al commit 99b40610956a (\u0027net: bridge: mcast: a\u00f1adir y aplicar el m\u00ednimo del intervalo de consulta\u0027), a\u00f1adir una comprobaci\u00f3n para el m\u00e1ximo del intervalo de consulta para solucionar este problema."
}
],
"id": "CVE-2025-39773",
"lastModified": "2026-10-19T21:10:00.160",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"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"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2025-09-11T17:15:43.010",
"references": [
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},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
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"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
},
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{
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{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
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"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-667"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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