CVE-2026-89744: device property: fix infinite loop in fwnode_for_each_child_node()

Severity: high (CVSS 8.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-11 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: device property: fix infinite loop in fwnode_for_each_child_node() When iterate over children of a fwnode that has a secondary fwnode, fwnode_get_next_child_node() can enter an infinite loop if the secondary fwnode has more than one child. Parent Child (Primary fwnode) FWa: {FWa1, FWa2, FWa3} (Secondary fwnode) FWb: {FWb1, FWb2} In this case: ┌─> fwnode_get_next_child_node(FWa, FWa1) │ - fwnode_call_ptr_op(FWa, get_next_child_node, FWa1) returns FWa2 │ │ ... │ │ fwnode_get_next_child_node(FWa, FWa3) │ - fwnode_call_ptr_op(FWa, get_next_child_node, FWa3) returns NULL │ - fwnode_call_ptr_op(FWb, get_next_child_node, FWa3) returns FWb1 │ │ fwnode_get_next_child_node(FWa, FWb1) │ - fwnode_call_ptr_op(FWa, get_next_child_node, FWb1) returns FWa1 └────┘ This cause fwnode_for_each_child_node() to loop indefinitely, reapeatedly output {FWa1, FWa2, FWa3, FWb1, FWa1, ...}. The root cause is that when the current child (FWb1) belongs to the secondary fwnode, calling get_next_child_node() on the parimary fwnode incorrectly returns the first child (FWa1) again instead of NULL. Fix this by dynamically checking the parent fwnode of the current child before calling get_next_child_node(). This approach follows the pattern established in commit b5b41ab6b0c1 ("device property: Check fwnode->secondary in fwnode_graph_get_next_endpoint()").

Affected products

Linux: from 5.10.253 before 5.10.273; from 5.15.203 before 5.15.224; from 6.1.167 before 6.1.188; from 6.6.130 before 6.6.157; from 6.12.78 before 6.12.109; from 6.18.19 before 6.18.50 — fixed in 5.10.273, 5.15.224, 6.1.188, 6.6.157, 6.12.109, 6.18.50

How to fix

Upgrade to a fixed version: Linux 5.10.273, 5.15.224, 6.1.188, 6.6.157. Check the vendor advisory for mitigations.

References

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