Live › vulnerability › CVE-2026-98881
Go to dashboardA leftover rcu_barrier() call in the Linux kernel bridge multicast teardown path blocks network namespace cleanup for long periods, holding the RTNL lock. The sources describe a stall and lock pressure rather than code execution or data theft.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running Linux kernels that include the bridge multicast code and that create and destroy network namespaces or bridge devices often, such as container hosts. The sources do not state fixed kernel versions or which stable releases carry the change.
No product ranges from the sources yet.
Unknown from the sources.
Unknown from the sources.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: remove stale rcu_barrier() in br_multicast_dev_del()
This rcu_barrier() came from a time call_rcu() calls were used in net/bridge/br_multicast.c.
Now kfree_rcu() is there, we can remove this problematic rcu_barrier() which causes extreme RTNL pressure in many syzbot reports.
INFO: task syz-executor:77945 is blocked on a mutex likely owned by task kworker/u1024:5:36537. task:kworker/u1024:5 state:D stack:24616 pid:36537 tgid:36537 ppid:2 task_flags:0x4208060 flags:0x00080000 last_sleep:612797637337 Workqueue: netns cleanup_net Call Trace: <TASK> [<ffffffff81914eaa>] context_switch+0xf2a/0x1730 kernel/sched/core.c:6483 [<ffffffff81201143>] __schedule+0x1133/0x43a0 kernel/sched/core.c:8411 [<ffffffff8120446b>] __schedule_loop kernel/sched/core.c:8514 [inline] [<ffffffff8120446b>] schedule+0xab/0x260 kernel/sched/core.c:8529 [<ffffffff8121a093>] schedule_timeout+0xc3/0x2b0 kernel/time/sleep_timeout.c:75 [<ffffffff81205347>] do_wait_for_common kernel/sched/completion.c:100 [inline] [<ffffffff81205347>] __wait_for_common kernel/sched/completion.c:121 [inline] [<ffffffff81205347>] wait_for_common kernel/sched/completion.c:132 [inline] [<ffffffff81205347>] wait_for_completion+0x2c7/0x5d0 kernel/sched/completion.c:153 [<ffffffff81b8f27f>] rcu_barrier+0x49f/0x620 kernel/rcu/tree.c:3888 [<ffffffff860091b3>] br_multicast_dev_del+0x303/0x350 net/bridge/br_multicast.c:4459 [<ffffffff85fb5dbc>] br_dev_uninit+0x1c/0x40 net/bridge/br_device.c:157 [<ffffffff8568058c>] unregister_netdevice_many_notify+0x1c1c/0x2300 net/core/dev.c:12599 [<ffffffff8562be43>] ops_exit_rtnl_list net/core/net_namespace.c:187 [inline] [<ffffffff8562be43>] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248
This page as .md · .json · in your agent: get_signal("CVE-2026-98881")
NVD data is provided by NIST and is public domain · EPSS scores by FIRST, used with attribution. Posts quoted belong to their authors.