Bug 2492854 (CVE-2026-53276)

Summary: CVE-2026-53276 kernel: Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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OS: Linux   
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Description OSIDB Bzimport 2026-06-25 10:09:10 UTC 
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer

In iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is
dropped:
	bis = iso_pi(sk)->conn->hcon;
	/* Release the socket before lookups since that requires hci_dev_lock
	 * which shall not be acquired while holding sock_lock for proper
	 * ordering.
	 */
	release_sock(sk);
	hci_dev_lock(bis->hdev);

During the unlocked window, could a concurrent close() destroy the connection
and free the bis structure, causing hci_dev_lock(bis->hdev) to access memory
after it is freed, fix this by using the hdev reference which was safely
acquired via iso_conn_get_hdev().
Comment 1 Keith Grant 2026-06-29 16:47:46 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062519-CVE-2026-53276-0959@gregkh/T