Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2022-48674

Disclosure Date: May 03, 2024
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

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

erofs: fix pcluster use-after-free on UP platforms

During stress testing with CONFIG_SMP disabled, KASAN reports as below:

==================================================================
BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30
Read of size 8 at addr ffff8881094223f8 by task stress/7789

CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
<TASK>
..
__mutex_lock+0xe5/0xc30
..
z_erofs_do_read_page+0x8ce/0x1560
..
z_erofs_readahead+0x31c/0x580
..
Freed by task 7787
kasan_save_stack+0x1e/0x40
kasan_set_track+0x20/0x30
kasan_set_free_info+0x20/0x40
__kasan_slab_free+0x10c/0x190
kmem_cache_free+0xed/0x380
rcu_core+0x3d5/0xc90
__do_softirq+0x12d/0x389

Last potentially related work creation:
kasan_save_stack+0x1e/0x40
__kasan_record_aux_stack+0x97/0xb0
call_rcu+0x3d/0x3f0
erofs_shrink_workstation+0x11f/0x210
erofs_shrink_scan+0xdc/0x170
shrink_slab.constprop.0+0x296/0x530
drop_slab+0x1c/0x70
drop_caches_sysctl_handler+0x70/0x80
proc_sys_call_handler+0x20a/0x2f0
vfs_write+0x555/0x6c0
ksys_write+0xbe/0x160
do_syscall_64+0x3b/0x90

The root cause is that erofs_workgroup_unfreeze() doesn’t reset to
orig_val thus it causes a race that the pcluster reuses unexpectedly
before freeing.

Since UP platforms are quite rare now, such path becomes unnecessary.
Let’s drop such specific-designed path directly instead.

Add Assessment

No one has assessed this topic. Be the first to add your voice to the community.

CVSS V3 Severity and Metrics
Base Score:
7.8 High
Impact Score:
5.9
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • linux

Products

  • linux kernel

Additional Info

Technical Analysis