CVE-2026-74528: Bluetooth: hci_sync: hold conn in hci_past_sync() callback

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_sync: hold conn in hci_past_sync() callback

Avoids giving freed pointers to hci_conn_valid(), which kmalloc may have
reused.

Hold refcount to avoid that.

The Linux kernel CVE team has assigned CVE-2026-74528 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.19 with commit d3413703d5f8b7d1e6f514f9440ed5da1bc30796 and fixed in 7.1.8 with commit e6792adef614b389141b142e30ee549e4a47dd7d
	Issue introduced in 6.19 with commit d3413703d5f8b7d1e6f514f9440ed5da1bc30796 and fixed in 7.2-rc6 with commit abf9753edf3f88282c44a605f3945d8d4f8dd86c

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-74528
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/bluetooth/hci_sync.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/e6792adef614b389141b142e30ee549e4a47dd7d
	https://git.kernel.org/stable/c/abf9753edf3f88282c44a605f3945d8d4f8dd86c