Bug 2516235 (CVE-2026-72042) - CVE-2026-72042 kernel: ipmi: Fix user refcount underflow in event delivery
Summary: CVE-2026-72042 kernel: ipmi: Fix user refcount underflow in event delivery
Keywords:
Status: NEW
Alias: CVE-2026-72042
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:01 UTC by OSIDB Bzimport
Modified: 2026-08-17 11:06 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-08-15 06:01:55 UTC
In the Linux kernel, the following vulnerability has been resolved:

ipmi: Fix user refcount underflow in event delivery

ipmi_alloc_recv_msg(user) takes the temporary user reference owned by the
receive message, and ipmi_free_recv_msg() drops it again. If event delivery
fails after allocating receive messages for earlier users,
handle_read_event_rsp() rolls those messages back with
ipmi_free_recv_msg().

That rollback path still drops user->refcount explicitly after freeing each
message. The extra put can free a user that remains linked on intf->users,
so later event delivery may dereference a freed user or trip refcount_t's
addition-on-zero warning when ipmi_alloc_recv_msg() tries to acquire
another reference.

Remove the stale explicit put and the now-dead user assignment. Keep the
list_del() and ipmi_free_recv_msg() calls; they are the required rollback
operations.


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