CVE-2026-97956 net: net_failover: Fix the deadlock in net_failover_slave_name_change()
A local attacker with high privileges can trigger a deadlock in the Linux kernel net_failover module, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97956?
CVE-2026-97956 is a denial of service vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: net_failover: Fix the deadlock in net_failover_slave_name_change()
This is a sibling fix of commit b84c5632c7b3 ("net: net_failover: Fix the deadlock in slave register"). There is netdev_lock_ops() in the upper callers, so using netif_open() instead of dev_open().
Call Trace: __schedule+0x2bb/0x650 schedule+0x27/0xb0 schedule_preempt_disabled+0x15/0x30 __mutex_lock.constprop.0+0x550/0xaf0 __mutex_lock_slowpath+0x13/0x20 mutex_lock+0x3b/0x50 dev_open+0x3b/0xe0 net_failover_slave_name_change+0x22/0x40 failover_event+0xd4/0x1e0 notifier_call_chain+0x62/0xf0 raw_notifier_call_chain+0x16/0x30 call_netdevice_notifiers_info+0x50/0x80 netif_change_name+0x200/0x330 do_setlink.isra.0+0xb12/0xdf0 ? security_capable+0x9a/0x1e0 ? ns_capable+0x31/0x60 rtnl_setlink+0x302/0x670 ? netlink_recvmsg+0x296/0x340 ? security_capable+0x9a/0x1e0 ? __pfx_rtnl_setlink+0x10/0x10 rtnetlink_rcv_msg+0x384/0x460 ? __pfx_rtnetlink_rcv_msg+0x10/0x10 netlink_rcv_skb+0x61/0x120 rtnetlink_rcv+0x15/0x30 netlink_unicast+0x28f/0x3c0 netlink_sendmsg+0x216/0x450 __sys_sendto+0x222/0x230 __x64_sys_sendto+0x24/0x40 x64_sys_call+0x1d5d/0x2390 do_syscall_64+0x105/0x5a0 ? do_syscall_64+0x140/0x5a0 ? exc_page_fault+0x94/0x1e0 entry_SYSCALL_64_after_hwframe+0x76/0x7e
Which versions are affected by CVE-2026-97956?
How do I fix CVE-2026-97956?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-97956 being exploited?
There is no known exploitation of CVE-2026-97956 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-97956, DEBIAN-CVE-2026-97956, GHSA-hv7q-v3g3-m28x, UBUNTU-CVE-2026-97956.