CVE-2026-98290: Bluetooth: RFCOMM: avoid socket lock inversion in listener cleanup

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

Bluetooth: RFCOMM: avoid socket lock inversion in listener cleanup

rfcomm_sock_cleanup_listen() closes unaccepted child sockets through
rfcomm_sock_close(), which takes the child socket lock before
rfcomm_dlc_close() acquires rfcomm_mutex. The RFCOMM worker takes these
locks in reverse order while handling connections and DLC state changes,
so lockdep reports a possible deadlock.

Close dequeued children without taking their socket lock. The accept queue
owns a reference to each child, and bt_accept_dequeue() locks the child
while unlinking it and clearing its parent pointer.

Dropping the child lock makes it important to prevent a concurrent
rfcomm_connect_ind() from enqueueing a new child after cleanup observes an
empty queue. Set a listening socket to BT_CLOSED while its lock is still
held, before dropping the lock and draining the queue. The state check in
rfcomm_connect_ind() then rejects new children once cleanup starts.

The Linux kernel CVE team has assigned CVE-2026-98290 to this issue.


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

	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 5.15.222 with commit eb4adaa46e4c9e6efa7be3ce06398f4d7c39b57c
	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 6.1.189 with commit 4aafb47301a799d3e01230d6568c4e93524e1523
	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 6.6.158 with commit c741977e413f5b49d306700820fb55ccb8269f5a
	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 6.12.112 with commit c6792c441767256030606eb82dca5d5fc360dd9a
	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 6.18.54 with commit bfce253f039eb5f58b810af267942a9f59207254
	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 7.2.8 with commit 18174b166547ef41973cc19feb5ef9cab39a8def
	Issue introduced in 5.15 with commit b7ce436a5d798bc59e71797952566608a4b4626b and fixed in 7.3-rc4 with commit 801fb950cae7048eb7d83b18857d1ca37b8cd5a4

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-2026-98290
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/rfcomm/sock.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/eb4adaa46e4c9e6efa7be3ce06398f4d7c39b57c
	https://git.kernel.org/stable/c/4aafb47301a799d3e01230d6568c4e93524e1523
	https://git.kernel.org/stable/c/c741977e413f5b49d306700820fb55ccb8269f5a
	https://git.kernel.org/stable/c/c6792c441767256030606eb82dca5d5fc360dd9a
	https://git.kernel.org/stable/c/bfce253f039eb5f58b810af267942a9f59207254
	https://git.kernel.org/stable/c/18174b166547ef41973cc19feb5ef9cab39a8def
	https://git.kernel.org/stable/c/801fb950cae7048eb7d83b18857d1ca37b8cd5a4