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CVE-2025-39773

net: bridge: fix soft lockup in br_multicast_query_expired() PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected d902eee43f1951b358d7347d9165c6af21cf7b1b before 34171b9e53bd1dc264f5556579f2b04f04435c73; affected d902eee43f1951b358d7347d9165c6af21cf7b1b before 43e281fde5e76a866a4d10780c35023f16c0e432; affected d902eee43f1951b358d7347d9165c6af21cf7b1b before 96476b043efb86a94f2badd260f7f99c97bd5893; affected d902eee43f1951b358d7347d9165c6af21cf7b1b before bdb19cd0de739870bb3494c815138b9dc30875c4; affected d902eee43f1951b358d7347d9165c6af21cf7b1b before 5bf5fce8a0c2a70d063af778fdb5b27238174cdd; affected d902eee43f1951b358d7347d9165c6af21cf7b1b before d1547bf460baec718b3398365f8de33d25c5f36f
Linux / Linuxaffected 2.6.34; unaffected 0 before 2.6.34; unaffected 5.15.190 through 5.15.*; unaffected 6.1.149 through 6.1.*; unaffected 6.6.103 through 6.6.*; unaffected 6.12.44 through 6.12.*; unaffected 6.16.4 through 6.16.*; unaffected 6.17 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

CVE

No English description supplied.

siemens-SADP

No English description supplied.