{"id":"AZL-74670","summary":"CVE-2025-39773 affecting package kernel for versions less than 5.15.200.1-1","details":"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'time' 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.","modified":"2026-04-01T05:22:45.654297Z","published":"2025-09-11T17:15:43Z","upstream":["CVE-2025-39773"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39773"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-74670.json"}}],"schema_version":"1.7.5"}