CVE-2026-53353

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

hsr: Remove WARN_ONCE() in hsr_addr_is_self().

syzbot reported the warning [0] in hsr_addr_is_self(),

whose assumption is simply wrong.

hsr->self_node is cleared in hsr_del_self_node(), which

is called from hsr_dellink().

Since dev->rtnl_link_ops->dellink() is called before

unregister_netdevice_many(), there is a window when

user can find the device but without hsr->self_node.

Let's remove WARN_ONCE() in hsr_addr_is_self().

[0]:

HSR: No self node

WARNING: net/hsr/hsr_framereg.c:39 at hsr_addr_is_self+0x211/0x3f0 net/hsr/hsr_framereg.c:39, CPU#0: syz.4.16848/17220

Modules linked in:

CPU: 0 UID: 0 PID: 17220 Comm: syz.4.16848 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}

Tainted: [L]=SOFTLOCKUP

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026

RIP: 0010:hsr_addr_is_self+0x211/0x3f0 net/hsr/hsr_framereg.c:39

Code: 33 2f 41 0f b7 dd 89 ee 09 de 31 ff e8 c8 b4 c

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References