Subject: CVE-2024-42294: block: fix deadlock between sd_remove & sd_release

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

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

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

block: fix deadlock between sd_remove & sd_release

Our test report the following hung task:

[ 2538.459400] INFO: task "kworker/0:0":7 blocked for more than 188 seconds.
[ 2538.459427] Call trace:
[ 2538.459430]  __switch_to+0x174/0x338
[ 2538.459436]  __schedule+0x628/0x9c4
[ 2538.459442]  schedule+0x7c/0xe8
[ 2538.459447]  schedule_preempt_disabled+0x24/0x40
[ 2538.459453]  __mutex_lock+0x3ec/0xf04
[ 2538.459456]  __mutex_lock_slowpath+0x14/0x24
[ 2538.459459]  mutex_lock+0x30/0xd8
[ 2538.459462]  del_gendisk+0xdc/0x350
[ 2538.459466]  sd_remove+0x30/0x60
[ 2538.459470]  device_release_driver_internal+0x1c4/0x2c4
[ 2538.459474]  device_release_driver+0x18/0x28
[ 2538.459478]  bus_remove_device+0x15c/0x174
[ 2538.459483]  device_del+0x1d0/0x358
[ 2538.459488]  __scsi_remove_device+0xa8/0x198
[ 2538.459493]  scsi_forget_host+0x50/0x70
[ 2538.459497]  scsi_remove_host+0x80/0x180
[ 2538.459502]  usb_stor_disconnect+0x68/0xf4
[ 2538.459506]  usb_unbind_interface+0xd4/0x280
[ 2538.459510]  device_release_driver_internal+0x1c4/0x2c4
[ 2538.459514]  device_release_driver+0x18/0x28
[ 2538.459518]  bus_remove_device+0x15c/0x174
[ 2538.459523]  device_del+0x1d0/0x358
[ 2538.459528]  usb_disable_device+0x84/0x194
[ 2538.459532]  usb_disconnect+0xec/0x300
[ 2538.459537]  hub_event+0xb80/0x1870
[ 2538.459541]  process_scheduled_works+0x248/0x4dc
[ 2538.459545]  worker_thread+0x244/0x334
[ 2538.459549]  kthread+0x114/0x1bc

[ 2538.461001] INFO: task "fsck.":15415 blocked for more than 188 seconds.
[ 2538.461014] Call trace:
[ 2538.461016]  __switch_to+0x174/0x338
[ 2538.461021]  __schedule+0x628/0x9c4
[ 2538.461025]  schedule+0x7c/0xe8
[ 2538.461030]  blk_queue_enter+0xc4/0x160
[ 2538.461034]  blk_mq_alloc_request+0x120/0x1d4
[ 2538.461037]  scsi_execute_cmd+0x7c/0x23c
[ 2538.461040]  ioctl_internal_command+0x5c/0x164
[ 2538.461046]  scsi_set_medium_removal+0x5c/0xb0
[ 2538.461051]  sd_release+0x50/0x94
[ 2538.461054]  blkdev_put+0x190/0x28c
[ 2538.461058]  blkdev_release+0x28/0x40
[ 2538.461063]  __fput+0xf8/0x2a8
[ 2538.461066]  __fput_sync+0x28/0x5c
[ 2538.461070]  __arm64_sys_close+0x84/0xe8
[ 2538.461073]  invoke_syscall+0x58/0x114
[ 2538.461078]  el0_svc_common+0xac/0xe0
[ 2538.461082]  do_el0_svc+0x1c/0x28
[ 2538.461087]  el0_svc+0x38/0x68
[ 2538.461090]  el0t_64_sync_handler+0x68/0xbc
[ 2538.461093]  el0t_64_sync+0x1a8/0x1ac

  T1:				T2:
  sd_remove
  del_gendisk
  __blk_mark_disk_dead
  blk_freeze_queue_start
  ++q->mq_freeze_depth
  				bdev_release
 				mutex_lock(&disk->open_mutex)
  				sd_release
 				scsi_execute_cmd
 				blk_queue_enter
 				wait_event(!q->mq_freeze_depth)
  mutex_lock(&disk->open_mutex)

SCSI does not set GD_OWNS_QUEUE, so QUEUE_FLAG_DYING is not set in
this scenario. This is a classic ABBA deadlock. To fix the deadlock,
make sure we don't try to acquire disk->open_mutex after freezing
the queue.

The Linux kernel CVE team has assigned CVE-2024-42294 to this issue.

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

	Issue introduced in 6.5 with commit eec1be4c30df and fixed in 6.6.44 with commit 5a5625a83eac
	Issue introduced in 6.5 with commit eec1be4c30df and fixed in 6.10.3 with commit f5418f48a93b
	Issue introduced in 6.5 with commit eec1be4c30df and fixed in 6.11 with commit 7e04da2dc701

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-2024-42294
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:
	block/genhd.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/5a5625a83eac91fdff1d5f0202ecfc45a31983c9
	https://git.kernel.org/stable/c/f5418f48a93b69ed9e6a2281eee06b412f14a544
	https://git.kernel.org/stable/c/7e04da2dc7013af50ed3a2beb698d5168d1e594b