Read the docs
TI-2025-26448 Aliases CVE-2025-39773GHSA-4vq6-c2m7-38vx

net: bridge: fix soft lockup in br_multicast_query_expired()

Priority LOW 24CWE-667Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-667 and the CVSS impact.

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.

Why it matters now

EPSS 0.00123 2nd percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.190, 6.1.149, 6.6.103 +3Red Hat: 5 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux2.6.34 and later5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4, 6.17Patch availableCNA
  • Linux VendorLinux Affected 2.6.34 and later Fixed in 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4, 6.17 Patch available CNA

CPE configurations NVD · 4

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*2.6.34 to before 5.15.190; 5.16 to before 6.1.149; 6.2 to before 6.6.103; 6.7 to before 6.12.44; 6.13 to before 6.16.4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*6.17 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*6.17 rc2VulnerableLinux
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.34 to before 5.15.190; 5.16 to before 6.1.149; 6.2 to before 6.6.103; 6.7 to before 6.12.44; 6.13 to before 6.16.4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* Versions 6.17 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* Versions 6.17 rc2 Vulnerable ·Linux
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.15.190, 6.1.149, 6.6.103, 6.12.44, 6.16.4, 6.17

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 8AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 9AffectedNo fix planned: Will not fix

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-39773
  2. 2026-10-03 Alias added: GHSA-4vq6-c2m7-38vx

References

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources