Bug 2513317 (CVE-2026-68393)

Summary: CVE-2026-68393 kernel: Bluetooth: hci_sync: extend conn_hash lookup critical sections
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Bluetooth hci_sync component of the Linux kernel. This vulnerability arises from the incorrect handling of Read-Copy-Update (RCU) protected pointers outside their designated critical sections without proper reference counting. An attacker could exploit this by triggering a race condition, leading to a Use-After-Free (UAF) error. This could result in system instability, denial of service, or potentially the execution of arbitrary code.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-10 12:30:35 UTC 
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_sync: extend conn_hash lookup critical sections

Using RCU-protected pointers outside the critical sections without
refcount is incorrect and may result to UAF.

Extend critical section to cover both hci_conn_hash lookup and use of
the returned conn.

Add surrounding rcu_read_lock() also when return value is not used, in
preparation for RCU lockdep requirement to hci_lookup_le_connect().

This avoids concurrent deletion of the conn before we are done
dereferencing it.

Also, make sure to hold hdev->lock when accessing hdev->accept_list.