linux-cve-announce - CVE-2023-53765: dm cache: free background tracker's queued work in btracker

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025120845-CVE-2023-53765-0317@gregkh>
Date: Mon,  8 Dec 2025 10:20:04 +0900
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2023-53765: dm cache: free background tracker's queued work in btracker_destroy

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

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

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

dm cache: free background tracker's queued work in btracker_destroy

Otherwise the kernel can BUG with:

[ 2245.426978] =============================================================================
[ 2245.435155] BUG bt_work (Tainted: G    B   W         ): Objects remaining in bt_work on __kmem_cache_shutdown()
[ 2245.445233] -----------------------------------------------------------------------------
[ 2245.445233]
[ 2245.454879] Slab 0x00000000b0ce2b30 objects=64 used=2 fp=0x000000000a3c6a4e flags=0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
[ 2245.467300] CPU: 7 PID: 10805 Comm: lvm Kdump: loaded Tainted: G    B   W          6.0.0-rc2 #19
[ 2245.476078] Hardware name: Dell Inc. PowerEdge R7525/0590KW, BIOS 2.5.6 10/06/2021
[ 2245.483646] Call Trace:
[ 2245.486100]  <TASK>
[ 2245.488206]  dump_stack_lvl+0x34/0x48
[ 2245.491878]  slab_err+0x95/0xcd
[ 2245.495028]  __kmem_cache_shutdown.cold+0x31/0x136
[ 2245.499821]  kmem_cache_destroy+0x49/0x130
[ 2245.503928]  btracker_destroy+0x12/0x20 [dm_cache]
[ 2245.508728]  smq_destroy+0x15/0x60 [dm_cache_smq]
[ 2245.513435]  dm_cache_policy_destroy+0x12/0x20 [dm_cache]
[ 2245.518834]  destroy+0xc0/0x110 [dm_cache]
[ 2245.522933]  dm_table_destroy+0x5c/0x120 [dm_mod]
[ 2245.527649]  __dm_destroy+0x10e/0x1c0 [dm_mod]
[ 2245.532102]  dev_remove+0x117/0x190 [dm_mod]
[ 2245.536384]  ctl_ioctl+0x1a2/0x290 [dm_mod]
[ 2245.540579]  dm_ctl_ioctl+0xa/0x20 [dm_mod]
[ 2245.544773]  __x64_sys_ioctl+0x8a/0xc0
[ 2245.548524]  do_syscall_64+0x5c/0x90
[ 2245.552104]  ? syscall_exit_to_user_mode+0x12/0x30
[ 2245.556897]  ? do_syscall_64+0x69/0x90
[ 2245.560648]  ? do_syscall_64+0x69/0x90
[ 2245.564394]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 2245.569447] RIP: 0033:0x7fe52583ec6b
...
[ 2245.646771] ------------[ cut here ]------------
[ 2245.651395] kmem_cache_destroy bt_work: Slab cache still has objects when called from btracker_destroy+0x12/0x20 [dm_cache]
[ 2245.651408] WARNING: CPU: 7 PID: 10805 at mm/slab_common.c:478 kmem_cache_destroy+0x128/0x130

Found using: lvm2-testsuite --only "cache-single-split.sh"

Ben bisected and found that commit 0495e337b703 ("mm/slab_common:
Deleting kobject in kmem_cache_destroy() without holding
slab_mutex/cpu_hotplug_lock") first exposed dm-cache's incomplete
cleanup of its background tracker work objects.

The Linux kernel CVE team has assigned CVE-2023-53765 to this issue.


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

	Fixed in 6.1.16 with commit 673a3af21d5e3ed769f3eaed0c888244290a3506
	Fixed in 6.2.3 with commit ed56ad5cacb7a3aeb611494d5d66e2399d2bfecc
	Fixed in 6.3 with commit 95ab80a8a0fef2ce0cc494a306dd283948066ce7

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-2023-53765
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:
	drivers/md/dm-cache-background-tracker.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/673a3af21d5e3ed769f3eaed0c888244290a3506
	https://git.kernel.org/stable/c/ed56ad5cacb7a3aeb611494d5d66e2399d2bfecc
	https://git.kernel.org/stable/c/95ab80a8a0fef2ce0cc494a306dd283948066ce7