CVE-2026-72040: ipmi: fix refcount leak in i_ipmi_request()

Severity: unknown
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: 2026-08-15 · updated 2026-08-23

Description

In the Linux kernel, the following vulnerability has been resolved: ipmi: fix refcount leak in i_ipmi_request() When a caller provides a `supplied_recv` message to i_ipmi_request(), the function increments the user's `nr_msgs` reference count. If an error occurs later, the out_err cleanup path only frees the recv_msg if the function allocated it itself (i.e., !supplied_recv). In the supplied_recv case the cleanup is skipped, leaving the reference count elevated. The caller ipmi_request_supply_msgs() does not release the supplied_recv on error, so the reference is permanently leaked. Fix this by explicitly reverting the reference count operations when a supplied recv_msg with a valid user pointer is present in the error path: decrement nr_msgs and drop the user's kref.

Affected products

Linux kernel: from 6.1.157 before 6.1.184; from 6.6.113 before 6.6.148; from 6.12.54 before 6.12.101; from 6.17.4 before 6.18; 6.18 — fixed in 6.1.184, 6.12.101, 6.18, 6.6.148, 7.2

How to fix

Upgrade to a fixed version: Linux kernel 6.1.184, 6.12.101, 6.18, 6.6.148. Check the vendor advisory for mitigations.

References

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