CVE-2025-38212: ipc: fix to protect IPCS lookups using RCU

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-04 · updated 2026-10-15
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: ipc: fix to protect IPCS lookups using RCU syzbot reported that it discovered a use-after-free vulnerability, [0] [0]: https://lore.kernel.org/all/67af13f8.050a0220.21dd3.0038.GAE@google.com/ idr_for_each() is protected by rwsem, but this is not enough. If it is not protected by RCU read-critical region, when idr_for_each() calls radix_tree_node_free() through call_rcu() to free the radix_tree_node structure, the node will be freed immediately, and when reading the next node in radix_tree_for_each_slot(), the already freed memory may be read. Therefore, we need to add code to make sure that idr_for_each() is protected within the RCU read-critical region when we call it in shm_destroy_orphaned().

Affected products

Debian Linux: 11.0
Linux kernel: from 3.1 before 5.4.295; from 5.5 before 5.10.239; from 5.11 before 5.15.186; from 5.16 before 6.1.142; from 6.2 before 6.6.95; from 6.7 before 6.12.35 — fixed in 5.10.239, 5.15.186, 5.4.295, 6.1.142, 6.12.35, 6.15.4

How to fix

Upgrade to a fixed version: Linux kernel 5.10.239, 5.15.186, 5.4.295, 6.1.142. Check the vendor advisory for mitigations.

References

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