CVE-2026-98881
Received
Received - Intake
RCU Barrier Removal in Linux Kernel Bridge Multicast
Vulnerability report for CVE-2026-98881, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-23
Last updated on: 2026-10-23
Assigner: kernel.org
Description
Description
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
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 |
| Linux | Linux | 0 |
| Linux | Linux | 0 |
| Linux | Linux | 0 |
| Linux | Linux | 0 |
| Linux | Linux | 0 |
| Linux | Linux | 0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
