Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:bpf, lockdown, audit: Fix buggy SELinux lockdown permission checks
Commit 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown")
added an implementation of the locked_down LSM hook to SELinux, with the aim
to restrict which domains are allowed to perform operations that would breach
lockdown. This is indirectly also getting audit subsystem involved to report
events. The latter is problematic, as reported by Ondrej and Serhei, since it
can bring down the whole system via audit:
1) The audit events that are triggered due to calls to security_locked_down()
can OOM kill a machine, see below details [0].
2) It also seems to be causing a deadlock via avc_has_perm()/slow_avc_audit()
when trying to wake up kauditd, for example, when using trace_sched_switch()
tracepoint, see details in [1]. Triggering this was not via some hypothetical
corner case, but with existing tools like runqlat & runqslower from bcc, for
example, which make use of this tracepoint. Rough call sequence goes like:
rq_lock(rq) -> -------------------------+
trace_sched_switch() -> |
bpf_prog_xyz() -> +-> deadlock
selinux_lockdown() -> |
audit_log_end() -> |
wake_up_interruptible() -> |
try_to_wake_up() -> |
rq_lock(rq) --------------+
What's worse is that the intention of 59438b46471a to further restrict lockdown
settings for specific applications in respect to the global lockdown policy is
completely broken for BPF. The SELinux policy rule for the current lockdown check
looks something like this:
allow <who> <who> : lockdown { <reason> };
However, this doesn't match with the 'current' task where the security_locked_down()
is executed, example: httpd does a syscall. There is a tracing program attached
to the syscall which triggers a BPF program to run, which ends up doing a
bpf_probe_read_kernel{,_str}() helper call. The selinux_lockdown() hook does
the permission check against 'current', that is, httpd in this example. httpd
has literally zero relation to this tracing program, and it would be nonsensical
having to write an SELinux policy rule against httpd to let the tracing helper
pass. The policy in this case needs to be against the entity that is installing
the BPF program. For example, if bpftrace would generate a histogram of syscall
counts by user space application:
bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @[comm] = count(); }'
bpftrace would then go and generate a BPF program from this internally. One way
of doing it [for the sake of the example] could be to call bpf_get_current_task()
helper and then access current->comm via one of bpf_probe_read_kernel{,_str}()
helpers. So the program itself has nothing to do with httpd or any other random
app doing a syscall here. The BPF program _explicitly initiated_ the lockdown
check. The allow/deny policy belongs in the context of bpftrace: meaning, you
want to grant bpftrace access to use these helpers, but other tracers on the
system like my_random_tracer _not_.
Therefore fix all three issues at the same time by taking a completely different
approach for the security_locked_down() hook, that is, move the check into the
program verification phase where we actually retrieve the BPF func proto. This
also reliably gets the task (current) that is trying to install the BPF tracing
program, e.g. bpftrace/bcc/perf/systemtap/etc, and it also fixes the OOM since
we're moving this out of the BPF helper's fast-path which can be called several
millions of times per second.
The check is then also in line with other security_locked_down() hooks in the
system where the enforcement is performed at open/load time, for example,
open_kcore() for /proc/kcore access or module_sig_check() for module signatures
just to pick f
---truncated---
SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having moderate severity.
| SUSE | |
|---|---|
| Base Score | 5.5 |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Local |
| Attack Complexity | Low |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
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 | Already fixed |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source-azure | Already fixed |
| 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 | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Micro 6.0 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 6.0 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Public Cloud 15 SP5 | kernel-source-azure | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Server 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source-azure | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source-azure | Already fixed |
| SUSE Manager Proxy 4.3 | kernel-default | Already fixed |
| SUSE Manager Proxy 4.3 | kernel-source | Already fixed |
| SUSE Manager Proxy 4.3 | kernel-source-azure | Already fixed |
| SUSE Manager Retail Branch Server 4.3 | kernel-default | Already fixed |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Already fixed |
| SUSE Manager Retail Branch Server 4.3 | kernel-source-azure | Already fixed |
| SUSE Manager Server 4.3 | kernel-default | Already fixed |
| SUSE Manager Server 4.3 | kernel-source | Already fixed |
| SUSE Manager Server 4.3 | kernel-source-azure | Already fixed |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Already fixed |
| openSUSE Leap 15.5 | kernel-source | Already fixed |
| openSUSE Leap 15.5 | kernel-source-azure | Already fixed |
| openSUSE Leap 15.5 | kernel-source-rt | Already fixed |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Already fixed |
| 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 | kernel-source-azure | 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 | kernel-source-azure | 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 | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source-azure | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-default | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Already fixed |
| 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 | Already fixed |
| 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 | Already fixed |
| SUSE Linux Enterprise Module for Public Cloud 15 SP4 | kernel-source-azure | Already fixed |
| 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 | kernel-source-azure | 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 | kernel-source-azure | 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 | Already fixed |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source-azure | Already fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Already fixed |
| 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 SP2 | kernel-source-azure | 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 SP3 | kernel-source-azure | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source-azure | Already fixed |
| 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 | kernel-source-azure | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-default | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-source-azure | Not affected |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 12 SP2 | 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 Module for Public Cloud 15 SP2 | kernel-source-azure | Not affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP3 | kernel-source-azure | Not affected |
| SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT | 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 | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Already fixed |
| 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 | Not affected |
| SUSE Linux Enterprise Server 12 SP2-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP2-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP2-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP2-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 Raspberry Pi 12 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP2 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP2 | 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-default | 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 4.1 | kernel-source-azure | Not affected |
| SUSE Manager Proxy 4.2 | kernel-source | Not affected |
| SUSE Manager Proxy 4.2 | kernel-source-azure | 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 4.1 | kernel-source-azure | Not affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source-azure | Not affected |
| SUSE Manager Server 4.0 | kernel-source | Not affected |
| SUSE Manager Server 4.1 | kernel-source | Not affected |
| SUSE Manager Server 4.1 | kernel-source-azure | Not affected |
| SUSE Manager Server 4.2 | kernel-source | Not affected |
| SUSE Manager Server 4.2 | kernel-source-azure | Not affected |
| SUSE OpenStack Cloud 7 | kernel-source | Not affected |
| SUSE OpenStack Cloud 8 | kernel-source | Not affected |
| SUSE OpenStack Cloud 9 | kernel-default | 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-default | 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 | Already fixed |
| openSUSE Leap 15.3 | kernel-source | Not affected |
| openSUSE Leap 15.3 | kernel-source-azure | Not affected |
| openSUSE Leap 15.3 | kernel-source-rt | Not affected |
| openSUSE Leap 15.4 | kernel-source | Already fixed |
| openSUSE Leap 15.4 | kernel-source-azure | Already fixed |
| openSUSE Leap 15.4 | kernel-source-rt | Already fixed |
| Products at an unknown state of their lifecycle. | ||
| SUSE Linux Enterprise Server LTSS Extended Security 12-SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12-SP5 | kernel-source-azure | Not affected |
SUSE Timeline for this CVE
CVE page created: Fri Mar 15 23:00:21 2024CVE page last modified: Tue Nov 12 19:32:43 2024