Subject: CVE-2024-50029: Bluetooth: hci_conn: Fix UAF in hci_enhanced_setup_sync

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

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

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

Bluetooth: hci_conn: Fix UAF in hci_enhanced_setup_sync

This checks if the ACL connection remains valid as it could be destroyed
while hci_enhanced_setup_sync is pending on cmd_sync leading to the
following trace:

BUG: KASAN: slab-use-after-free in hci_enhanced_setup_sync+0x91b/0xa60
Read of size 1 at addr ffff888002328ffd by task kworker/u5:2/37

CPU: 0 UID: 0 PID: 37 Comm: kworker/u5:2 Not tainted 6.11.0-rc6-01300-g810be445d8d6 #7099
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x5d/0x80
 ? hci_enhanced_setup_sync+0x91b/0xa60
 print_report+0x152/0x4c0
 ? hci_enhanced_setup_sync+0x91b/0xa60
 ? __virt_addr_valid+0x1fa/0x420
 ? hci_enhanced_setup_sync+0x91b/0xa60
 kasan_report+0xda/0x1b0
 ? hci_enhanced_setup_sync+0x91b/0xa60
 hci_enhanced_setup_sync+0x91b/0xa60
 ? __pfx_hci_enhanced_setup_sync+0x10/0x10
 ? __pfx___mutex_lock+0x10/0x10
 hci_cmd_sync_work+0x1c2/0x330
 process_one_work+0x7d9/0x1360
 ? __pfx_lock_acquire+0x10/0x10
 ? __pfx_process_one_work+0x10/0x10
 ? assign_work+0x167/0x240
 worker_thread+0x5b7/0xf60
 ? __kthread_parkme+0xac/0x1c0
 ? __pfx_worker_thread+0x10/0x10
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x293/0x360
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x2f/0x70
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 34:
 kasan_save_stack+0x30/0x50
 kasan_save_track+0x14/0x30
 __kasan_kmalloc+0x8f/0xa0
 __hci_conn_add+0x187/0x17d0
 hci_connect_sco+0x2e1/0xb90
 sco_sock_connect+0x2a2/0xb80
 __sys_connect+0x227/0x2a0
 __x64_sys_connect+0x6d/0xb0
 do_syscall_64+0x71/0x140
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 37:
 kasan_save_stack+0x30/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3b/0x60
 __kasan_slab_free+0x101/0x160
 kfree+0xd0/0x250
 device_release+0x9a/0x210
 kobject_put+0x151/0x280
 hci_conn_del+0x448/0xbf0
 hci_abort_conn_sync+0x46f/0x980
 hci_cmd_sync_work+0x1c2/0x330
 process_one_work+0x7d9/0x1360
 worker_thread+0x5b7/0xf60
 kthread+0x293/0x360
 ret_from_fork+0x2f/0x70
 ret_from_fork_asm+0x1a/0x30

The Linux kernel CVE team has assigned CVE-2024-50029 to this issue.

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

	Issue introduced in 6.1 with commit e07a06b4eb41 and fixed in 6.6.57 with commit 867639300759
	Issue introduced in 6.1 with commit e07a06b4eb41 and fixed in 6.11.4 with commit 98ccd44002d8
	Issue introduced in 6.1 with commit e07a06b4eb41 and fixed in 6.12-rc3 with commit 18fd04ad856d

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-2024-50029
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_conn.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/867639300759e3e1c5b1e1a5ff89231f263a32a7
	https://git.kernel.org/stable/c/98ccd44002d88cbf4edfc4480df532a3da5a013e
	https://git.kernel.org/stable/c/18fd04ad856df07733f5bb07e7f7168e7443d393