Bug 2516525 (CVE-2026-72022)

Summary: CVE-2026-72022 kernel: llc: fix SAP refcount leak in llc_ui_autobind()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Logical Link Control (LLC) subsystem. The `llc_ui_autobind()` function fails to properly release a reference to a Service Access Point (SAP) after a successful autobind operation. A local user can repeatedly perform autobind and close cycles, which leads to the exhaustion of all dynamic SAP values. This can result in a denial of service, preventing subsequent autobind operations from succeeding.
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Description OSIDB Bzimport 2026-08-15 06:17:05 UTC 
In the Linux kernel, the following vulnerability has been resolved:

llc: fix SAP refcount leak in llc_ui_autobind()

llc_ui_autobind() opens a SAP after choosing a dynamic LSAP.
llc_sap_open() returns a reference owned by the caller, and
llc_sap_add_socket() takes a second reference for the socket's
membership in the SAP hash tables.

llc_ui_bind() drops the caller's reference after adding the socket,
but llc_ui_autobind() keeps it. When the socket is closed,
llc_sap_remove_socket() releases only the socket reference, leaving
the SAP on llc_sap_list with sk_count == 0.

This is user-visible because repeated autobind and close cycles can consume
all dynamic SAP values and make later autobinds fail with -EUSERS.

Drop the caller's reference after a successful autobind, matching
llc_ui_bind()'s ownership model.
Comment 1 Keith Grant 2026-08-17 16:17:49 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081510-CVE-2026-72022-764c@gregkh/T