Upstream information

CVE-2021-47634 at MITRE

Description

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

ubi: Fix race condition between ctrl_cdev_ioctl and ubi_cdev_ioctl

Hulk Robot reported a KASAN report about use-after-free:
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0x13d/0x160
Read of size 8 at addr ffff888035e37d98 by task ubiattach/1385
[...]
Call Trace:
klist_dec_and_del+0xa7/0x4a0
klist_put+0xc7/0x1a0
device_del+0x4d4/0xed0
cdev_device_del+0x1a/0x80
ubi_attach_mtd_dev+0x2951/0x34b0 [ubi]
ctrl_cdev_ioctl+0x286/0x2f0 [ubi]

Allocated by task 1414:
device_add+0x60a/0x18b0
cdev_device_add+0x103/0x170
ubi_create_volume+0x1118/0x1a10 [ubi]
ubi_cdev_ioctl+0xb7f/0x1ba0 [ubi]

Freed by task 1385:
cdev_device_del+0x1a/0x80
ubi_remove_volume+0x438/0x6c0 [ubi]
ubi_cdev_ioctl+0xbf4/0x1ba0 [ubi]
[...]
==================================================================

The lock held by ctrl_cdev_ioctl is ubi_devices_mutex, but the lock held
by ubi_cdev_ioctl is ubi->device_mutex. Therefore, the two locks can be
concurrent.

ctrl_cdev_ioctl contains two operations: ubi_attach and ubi_detach.
ubi_detach is bug-free because it uses reference counting to prevent
concurrency. However, uif_init and uif_close in ubi_attach may race with
ubi_cdev_ioctl.

uif_init will race with ubi_cdev_ioctl as in the following stack.
cpu1 cpu2 cpu3
_______________________|________________________|______________________
ctrl_cdev_ioctl
ubi_attach_mtd_dev
uif_init
ubi_cdev_ioctl
ubi_create_volume
cdev_device_add
ubi_add_volume
// sysfs exist
kill_volumes
ubi_cdev_ioctl
ubi_remove_volume
cdev_device_del
// first free
ubi_free_volume
cdev_del
// double free
cdev_device_del

And uif_close will race with ubi_cdev_ioctl as in the following stack.
cpu1 cpu2 cpu3
_______________________|________________________|______________________
ctrl_cdev_ioctl
ubi_attach_mtd_dev
uif_init
ubi_cdev_ioctl
ubi_create_volume
cdev_device_add
ubi_debugfs_init_dev
//error goto out_uif;
uif_close
kill_volumes
ubi_cdev_ioctl
ubi_remove_volume
cdev_device_del
// first free
ubi_free_volume
// double free

The cause of this problem is that commit 714fb87e8bc0 make device
"available" before it becomes accessible via sysfs. Therefore, we
roll back the modification. We will fix the race condition between
ubi device creation and udev by removing ubi_get_device in
vol_attribute_show and dev_attribute_show.This avoids accessing
uninitialized ubi_devices[ubi_num].

ubi_get_device is used to prevent devices from being deleted during
sysfs execution. However, now kernfs ensures that devices will not
be deleted before all reference counting are released.
The key process is shown in the following stack.

device_del
device_remove_attrs
device_remove_groups
sysfs_remove_groups
sysfs_remove_group
remove_files
kernfs_remove_by_name
kernfs_remove_by_name_ns
__kernfs_remove
kernfs_drain

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having important severity.

CVSS v3 Scores
  SUSE
Base Score 6.4
Vector CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity High
Privileges Required High
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
Availability Impact High
CVSSv3 Version 3.1
CVSS v4 Scores
  SUSE
Base Score 7.1
Vector CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Attack Vector Local
Attack Complexity High
Attack Requirements Present
Privileges Required High
User Interaction None
Vulnerable System Confidentiality Impact High
Vulnerable System Integrity Impact High
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0
SUSE Bugzilla entry: 1237758 [NEW]

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Desktop 15 SP6 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source-azure Not affected
SUSE Linux Enterprise Live Patching 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Live Patching 15 SP6 kernel-source Not affected
SUSE Linux Enterprise Micro 5.1 kernel-default Affected
SUSE Linux Enterprise Micro 5.1 kernel-rt Affected
SUSE Linux Enterprise Micro 5.1 kernel-source Affected
SUSE Linux Enterprise Micro 5.1 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.2 kernel-default Affected
SUSE Linux Enterprise Micro 5.2 kernel-rt Affected
SUSE Linux Enterprise Micro 5.2 kernel-source Affected
SUSE Linux Enterprise Micro 5.2 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.3 kernel-default Affected
SUSE Linux Enterprise Micro 5.3 kernel-rt Affected
SUSE Linux Enterprise Micro 5.3 kernel-source Affected
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-default Affected
SUSE Linux Enterprise Micro 5.4 kernel-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-source Affected
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.5 kernel-default Affected
SUSE Linux Enterprise Micro 5.5 kernel-source Affected
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-source Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-source Not affected
SUSE Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure Not affected
SUSE Linux Enterprise Real Time 15 SP6 kernel-source-rt Not affected
SUSE Linux Enterprise Server 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Server 15 SP6 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP6 kernel-source-azure Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source-azure Not affected
SUSE Linux Enterprise Workstation Extension 15 SP6 kernel-default Not affected
SUSE Linux Enterprise Workstation Extension 15 SP6 kernel-source Not affected
SUSE Linux Micro 6.0 kernel-default Not affected
SUSE Linux Micro 6.0 kernel-source Not affected
SUSE Linux Micro 6.0 kernel-source-rt Not affected
SUSE Linux Micro 6.1 kernel-default Not affected
SUSE Linux Micro 6.1 kernel-source Not affected
SUSE Linux Micro 6.1 kernel-source-rt Not affected
SUSE Manager Proxy 4.3 kernel-default Affected
SUSE Manager Proxy 4.3 kernel-source Affected
SUSE Manager Retail Branch Server 4.3 kernel-default Affected
SUSE Manager Retail Branch Server 4.3 kernel-source Affected
SUSE Manager Server 4.3 kernel-default Affected
SUSE Manager Server 4.3 kernel-source Affected
SUSE Real Time Module 15 SP6 kernel-source-rt Not affected
openSUSE Leap 15.6 kernel-default Not affected
openSUSE Leap 15.6 kernel-source Not affected
openSUSE Leap 15.6 kernel-source-azure Not affected
openSUSE Leap 15.6 kernel-source-rt Not affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Availability Extension 12 SP5 kernel-default Affected
SUSE Linux Enterprise High Availability Extension 12 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source-azure Unsupported
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP3 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP3 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure Unsupported
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default Not affected
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source Not affected
SUSE Linux Enterprise Server 12 SP5 kernel-source Affected
SUSE Linux Enterprise Server 12 SP5 kernel-source-azure Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source-azure Affected
SUSE Linux Enterprise Server 15 SP3 kernel-source Affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP5 kernel-source Affected
SUSE Linux Enterprise Server 15 SP5 kernel-source-azure Unsupported
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source Affected
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source-azure Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source-azure Unsupported
Products past their end of life and not receiving proactive updates anymore.
SUSE CaaS Platform 4.0 kernel-source Affected
SUSE Enterprise Storage 6 kernel-source Affected
SUSE Enterprise Storage 7 kernel-source Affected
SUSE Enterprise Storage 7.1 kernel-source Affected
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Not affected
SUSE Linux Enterprise Desktop 12 SP2 kernel-source Affected
SUSE Linux Enterprise Desktop 12 SP4 kernel-source Affected
SUSE Linux Enterprise Desktop 15 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP4 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15-LTSS kernel-source Affected
SUSE Linux Enterprise Micro 5.0 kernel-default Affected
SUSE Linux Enterprise Module for Basesystem 15 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Affected
SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Affected
SUSE Linux Enterprise Server 11 SP4 kernel-source Not affected
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-default Not affected
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-source Not affected
SUSE Linux Enterprise Server 11 SP4-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 12 SP2 kernel-source Affected
SUSE Linux Enterprise Server 12 SP2-BCL kernel-source Affected
SUSE Linux Enterprise Server 12 SP2-ESPOS kernel-source Affected
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise Server 12 SP4 kernel-source Affected
SUSE Linux Enterprise Server 12 SP4-ESPOS kernel-source Affected
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 kernel-source Affected
SUSE Linux Enterprise Server 15 SP1 kernel-source Affected
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP2 kernel-source Affected
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Affected
SUSE Linux Enterprise Server 15-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15-LTSS kernel-source Affected
SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Affected
SUSE Manager Proxy 4.0 kernel-source Affected
SUSE Manager Proxy 4.1 kernel-source Affected
SUSE Manager Proxy 4.2 kernel-source Affected
SUSE Manager Retail Branch Server 4.0 kernel-source Affected
SUSE Manager Retail Branch Server 4.1 kernel-source Affected
SUSE Manager Retail Branch Server 4.2 kernel-source Affected
SUSE Manager Server 4.0 kernel-source Affected
SUSE Manager Server 4.1 kernel-source Affected
SUSE Manager Server 4.2 kernel-source Affected
SUSE OpenStack Cloud 7 kernel-source Affected
SUSE OpenStack Cloud 9 kernel-source Affected
SUSE OpenStack Cloud Crowbar 9 kernel-source Affected
SUSE Real Time Module 15 SP3 kernel-source-rt Affected
SUSE Real Time Module 15 SP4 kernel-source-rt Affected
SUSE Real Time Module 15 SP5 kernel-source-rt Affected
openSUSE Leap 15.3 kernel-source Affected
openSUSE Leap 15.3 kernel-source-rt Affected
openSUSE Leap 15.4 kernel-source Affected
openSUSE Leap 15.4 kernel-source-azure Unsupported
openSUSE Leap 15.4 kernel-source-rt Affected
openSUSE Leap 15.5 kernel-source Affected
openSUSE Leap 15.5 kernel-source-azure Unsupported
openSUSE Leap 15.5 kernel-source-rt Affected


SUSE Timeline for this CVE

CVE page created: Wed Feb 26 04:05:46 2025
CVE page last modified: Wed Feb 26 13:46:10 2025