Upstream information

CVE-2024-43891 at MITRE

Description

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

tracing: Have format file honor EVENT_FILE_FL_FREED

When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).

All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.

A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them. The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.

This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:

In one console run:

# cd tools/testing/selftests/user_events
# while true; do ./ftrace_test; done

And in another console run:

# cd /sys/kernel/tracing/
# while true; do cat events/user_events/__test_event/format; done 2>/dev/null

With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.

After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having moderate severity.

CVSS v3 Scores
  National Vulnerability Database SUSE
Base Score 4.7 6.4
Vector CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local Local
Attack Complexity High High
Privileges Required Low High
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact None High
Integrity Impact None High
Availability Impact High High
CVSSv3 Version 3.1 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: 1229762 [RESOLVED / INVALID]

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 SP5 kernel-default Not affected
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Not affected
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 SP5 kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source-azure 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 Micro 5.1 kernel-default Not affected
SUSE Linux Enterprise Micro 5.1 kernel-rt Not affected
SUSE Linux Enterprise Micro 5.1 kernel-source-rt Not affected
SUSE Linux Enterprise Micro 5.2 kernel-default Not affected
SUSE Linux Enterprise Micro 5.2 kernel-rt Not affected
SUSE Linux Enterprise Micro 5.2 kernel-source-rt Not affected
SUSE Linux Enterprise Micro 5.3 kernel-default Not affected
SUSE Linux Enterprise Micro 5.3 kernel-rt Not affected
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Not affected
SUSE Linux Enterprise Micro 5.4 kernel-default Not affected
SUSE Linux Enterprise Micro 5.4 kernel-rt Not affected
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Not affected
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Not affected
SUSE Linux Enterprise Micro 6.0 kernel-default Not affected
SUSE Linux Enterprise Micro 6.0 kernel-source Not affected
SUSE Linux Enterprise Micro 6.0 kernel-source-rt Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-default Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Not 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 SP5 kernel-default Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP5 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 SP5 kernel-source-azure Not affected
SUSE Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure Not affected
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Not affected
SUSE Linux Enterprise Real Time 15 SP6 kernel-source-rt Not affected
SUSE Linux Enterprise Server 15 SP5 kernel-default Not affected
SUSE Linux Enterprise Server 15 SP5 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP5 kernel-source-azure 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 SP5 kernel-default Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 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 Manager Proxy 4.3 kernel-default Not affected
SUSE Manager Proxy 4.3 kernel-source Not affected
SUSE Manager Retail Branch Server 4.3 kernel-default Not affected
SUSE Manager Retail Branch Server 4.3 kernel-source Not affected
SUSE Manager Server 4.3 kernel-default Not affected
SUSE Manager Server 4.3 kernel-source Not affected
SUSE Real Time Module 15 SP5 kernel-source-rt Not affected
SUSE Real Time Module 15 SP6 kernel-source-rt Not affected
openSUSE Leap 15.5 kernel-default Not affected
openSUSE Leap 15.5 kernel-source Not affected
openSUSE Leap 15.5 kernel-source-azure Not affected
openSUSE Leap 15.5 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 Desktop 15 SP4 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source-azure Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Not affected
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-default Not affected
SUSE Linux Enterprise Server 12 SP5 kernel-source Not affected
SUSE Linux Enterprise Server 12 SP5 kernel-source-azure Not affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source-azure Not affected
SUSE Linux Enterprise Server 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Not affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 15 SP3 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Not affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 15 SP4 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Not affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-default Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source-azure Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-default Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Not affected
Products past their end of life and not receiving proactive updates anymore.
HPE Helion OpenStack 8 kernel-source Not affected
SUSE CaaS Platform 4.0 kernel-source Not affected
SUSE CaaS Platform Toolchain 3 kernel-source Not affected
SUSE Enterprise Storage 6 kernel-source Not affected
SUSE Enterprise Storage 7 kernel-source Not affected
SUSE Enterprise Storage 7.1 kernel-source Not affected
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Not affected
SUSE Linux Enterprise Desktop 12 SP3 kernel-source Not affected
SUSE Linux Enterprise Desktop 12 SP4 kernel-source Not affected
SUSE Linux Enterprise Desktop 15 kernel-source Not affected
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Not affected
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15-ESPOS kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15-LTSS kernel-source Not affected
SUSE Linux Enterprise Micro 5.0 kernel-default Not affected
SUSE Linux Enterprise Module for Basesystem 15 kernel-source Not affected
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Not affected
SUSE Linux Enterprise Module for Development Tools 15 kernel-source Not affected
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Not affected
SUSE Linux Enterprise Real Time 12 SP5 kernel-source-rt Not affected
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Not affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source-rt Not affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Not affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Not 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 SP3 kernel-source Not affected
SUSE Linux Enterprise Server 12 SP3-BCL kernel-source Not affected
SUSE Linux Enterprise Server 12 SP3-ESPOS kernel-source Not affected
SUSE Linux Enterprise Server 12 SP3-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 12 SP4 kernel-source Not affected
SUSE Linux Enterprise Server 12 SP4-ESPOS kernel-source Not affected
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default Not affected
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 15 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP1 kernel-source Not affected
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Not affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Not affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Not affected
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Not affected
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Not affected
SUSE Linux Enterprise Server 15-LTSS kernel-default Not affected
SUSE Linux Enterprise Server 15-LTSS kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP3 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Not affected
SUSE Manager Proxy 4.0 kernel-source Not affected
SUSE Manager Proxy 4.1 kernel-source Not affected
SUSE Manager Proxy 4.2 kernel-source Not affected
SUSE Manager Retail Branch Server 4.0 kernel-source Not affected
SUSE Manager Retail Branch Server 4.1 kernel-source Not affected
SUSE Manager Retail Branch Server 4.2 kernel-source Not affected
SUSE Manager Server 4.0 kernel-source Not affected
SUSE Manager Server 4.1 kernel-source Not affected
SUSE Manager Server 4.2 kernel-source Not affected
SUSE OpenStack Cloud 8 kernel-source Not affected
SUSE OpenStack Cloud 9 kernel-source Not affected
SUSE OpenStack Cloud Crowbar 8 kernel-source Not affected
SUSE OpenStack Cloud Crowbar 9 kernel-source Not affected
SUSE Real Time Module 15 SP3 kernel-source-rt Not affected
SUSE Real Time Module 15 SP4 kernel-source-rt Not affected
openSUSE Leap 15.3 kernel-source Not affected
openSUSE Leap 15.3 kernel-source-rt Not affected
openSUSE Leap 15.4 kernel-source Not affected
openSUSE Leap 15.4 kernel-source-azure Not affected
openSUSE Leap 15.4 kernel-source-rt Not affected
Products at an unknown state of their lifecycle.
SUSE Linux Enterprise Server 12 SP5 LTSS Extended Security kernel-source Not affected
SUSE Linux Enterprise Server 12 SP5 LTSS Extended Security kernel-source-azure Not affected


SUSE Timeline for this CVE

CVE page created: Mon Aug 26 17:51:00 2024
CVE page last modified: Tue Nov 12 15:14:51 2024