Upstream information

CVE-2024-50066 at MITRE

Description

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

mm/mremap: fix move_normal_pmd/retract_page_tables race

In mremap(), move_page_tables() looks at the type of the PMD entry and the
specified address range to figure out by which method the next chunk of
page table entries should be moved.

At that point, the mmap_lock is held in write mode, but no rmap locks are
held yet. For PMD entries that point to page tables and are fully covered
by the source address range, move_pgt_entry(NORMAL_PMD, ...) is called,
which first takes rmap locks, then does move_normal_pmd().
move_normal_pmd() takes the necessary page table locks at source and
destination, then moves an entire page table from the source to the
destination.

The problem is: The rmap locks, which protect against concurrent page
table removal by retract_page_tables() in the THP code, are only taken
after the PMD entry has been read and it has been decided how to move it.
So we can race as follows (with two processes that have mappings of the
same tmpfs file that is stored on a tmpfs mount with huge=advise); note
that process A accesses page tables through the MM while process B does it
through the file rmap:

process A process B
========= =========
mremap
mremap_to
move_vma
move_page_tables
get_old_pmd
alloc_new_pmd
*** PREEMPT ***
madvise(MADV_COLLAPSE)
do_madvise
madvise_walk_vmas
madvise_vma_behavior
madvise_collapse
hpage_collapse_scan_file
collapse_file
retract_page_tables
i_mmap_lock_read(mapping)
pmdp_collapse_flush
i_mmap_unlock_read(mapping)
move_pgt_entry(NORMAL_PMD, ...)
take_rmap_locks
move_normal_pmd
drop_rmap_locks

When this happens, move_normal_pmd() can end up creating bogus PMD entries
in the line `pmd_populate(mm, new_pmd, pmd_pgtable(pmd))`. The effect
depends on arch-specific and machine-specific details; on x86, you can end
up with physical page 0 mapped as a page table, which is likely
exploitable for user->kernel privilege escalation.

Fix the race by letting process B recheck that the PMD still points to a
page table after the rmap locks have been taken. Otherwise, we bail and
let the caller fall back to the PTE-level copying path, which will then
bail immediately at the pmd_none() check.

Bug reachability: Reaching this bug requires that you can create
shmem/file THP mappings - anonymous THP uses different code that doesn't
zap stuff under rmap locks. File THP is gated on an experimental config
flag (CONFIG_READ_ONLY_THP_FOR_FS), so on normal distro kernels you need
shmem THP to hit this bug. As far as I know, getting shmem THP normally
requires that you can mount your own tmpfs with the right mount flags,
which would require creating your own user+mount namespace; though I don't
know if some distros maybe enable shmem THP by default or something like
that.

Bug impact: This issue can likely be used for user->kernel privilege
escalation when it is reachable.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having moderate severity.

CVSS v3 Scores
  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
SUSE Bugzilla entry: 1232078 [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 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 Availability Extension 12 SP5 kernel-default Not affected
SUSE Linux Enterprise High Availability Extension 12 SP5 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 12 kernel-default Unsupported
SUSE Linux Enterprise High Performance Computing 12 kernel-source Unsupported
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 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 Live Patching 12 SP5 kernel-default Not affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Not affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Not affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source 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 Not affected
SUSE Linux Enterprise Micro 5.1 kernel-rt Not affected
SUSE Linux Enterprise Micro 5.1 kernel-source 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 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 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 Not affected
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Not affected
SUSE Linux Enterprise Micro 5.5 kernel-default Not affected
SUSE Linux Enterprise Micro 5.5 kernel-source 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 12 kernel-default Unsupported
SUSE Linux Enterprise Module for Public Cloud 12 kernel-source Unsupported
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 12 SP5 kernel-source-rt 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 12 SP5 kernel-default Unsupported
SUSE Linux Enterprise Server 12 SP5 kernel-source Unsupported
SUSE Linux Enterprise Server 12 SP5 kernel-source-azure Not affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default 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 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 12 SP5 kernel-default Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP5 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 Linux Enterprise Software Development Kit 12 SP5 kernel-default Not affected
SUSE Linux Enterprise Software Development Kit 12 SP5 kernel-source Not affected
SUSE Linux Enterprise Workstation Extension 12 SP5 kernel-default Not affected
SUSE Linux Enterprise Workstation Extension 12 SP5 kernel-source 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 Unsupported
openSUSE Leap 15.5 kernel-source-rt Unsupported
openSUSE Leap 15.6 kernel-default Not affected
openSUSE Leap 15.6 kernel-source Not affected
openSUSE Leap 15.6 kernel-source-azure Unsupported
openSUSE Leap 15.6 kernel-source-rt Unsupported
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 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 Live Patching 15 SP2 kernel-default Not affected
SUSE Linux Enterprise Live Patching 15 SP2 kernel-source Not affected
SUSE Linux Enterprise Live Patching 15 SP3 kernel-default Not affected
SUSE Linux Enterprise Live Patching 15 SP3 kernel-source Not affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Not affected
SUSE Linux Enterprise Live Patching 15 SP4 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 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 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 SP1 kernel-source Unsupported
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 Point of Sale 12 SP2-CLIENT kernel-source 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 kernel-default Unsupported
SUSE Linux Enterprise Server 12 kernel-source Unsupported
SUSE Linux Enterprise Server 12 SP1 kernel-source Unsupported
SUSE Linux Enterprise Server 12 SP1-LTSS kernel-source Unsupported
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-default Unsupported
SUSE Linux Enterprise Server 12 SP3 kernel-source Unsupported
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-default Unsupported
SUSE Linux Enterprise Server 12 SP4 kernel-source Unsupported
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 kernel-default Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 kernel-source Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP1 kernel-source Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 12 SP3 kernel-default Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP3 kernel-source Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-default Unsupported
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Unsupported
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 7 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 Unsupported
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: Wed Oct 23 08:00:00 2024
CVE page last modified: Mon Oct 28 12:07:50 2024