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CBL Mariner 2.0 Security Update: kernel (CVE-2024-49878)

medium Nessus Plugin ID 212843

Synopsis

The remote CBL Mariner host is missing one or more security updates.

Description

The version of kernel installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2024-49878 advisory.

 - In the Linux kernel, the following vulnerability has been resolved: resource: fix region_intersects() vs add_memory_driver_managed() On a system with CXL memory, the resource tree (/proc/iomem) related to CXL memory May look like something as follows. 490000000-50fffffff : CXL Window 0 490000000-50fffffff :
 region0 490000000-50fffffff : dax0.0 490000000-50fffffff : System RAM (kmem) Because drivers/dax/kmem.c calls add_memory_driver_managed() during onlining CXL memory, which makes System RAM (kmem) a descendant of CXL Window X. This confuses region_intersects(), which expects all System RAM resources to be at the top level of iomem_resource. This can lead to bugs. For example, when the following command line is executed to write some memory in CXL memory range via /dev/mem, $ dd if=data of=/dev/mem bs=$((1 << 10)) seek=$((0x490000000 >> 10)) count=1 dd: error writing '/dev/mem': Bad address 1+0 records in 0+0 records out 0 bytes copied, 0.0283507 s, 0.0 kB/s the command fails as expected. However, the error code is wrong.
 It should be Operation not permitted instead of Bad address. More seriously, the /dev/mem permission checking in devmem_is_allowed() passes incorrectly. Although the accessing is prevented later because ioremap() isn't allowed to map system RAM, it is a potential security issue. During command executing, the following warning is reported in the kernel log for calling ioremap() on system RAM. ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216
 __ioremap_caller.constprop.0+0x131/0x35d Call Trace: memremap+0xcb/0x184 xlate_dev_mem_ptr+0x25/0x2f write_mem+0x94/0xfb vfs_write+0x128/0x26d ksys_write+0xac/0xfe do_syscall_64+0x9a/0xfd entry_SYSCALL_64_after_hwframe+0x4b/0x53 The details of command execution process are as follows. In the above resource tree, System RAM is a descendant of CXL Window 0 instead of a top level resource. So, region_intersects() will report no System RAM resources in the CXL memory region incorrectly, because it only checks the top level resources. Consequently, devmem_is_allowed() will return 1 (allow access via /dev/mem) for CXL memory region incorrectly. Fortunately, ioremap() doesn't allow to map System RAM and reject the access. So, region_intersects() needs to be fixed to work correctly with the resource tree with System RAM not at top level as above. To fix it, if we found a unmatched resource in the top level, we will continue to search matched resources in its descendant resources. So, we will not miss any matched resources in resource tree anymore. In the new implementation, an example resource tree |------------- CXL Window 0 ------------| |-- System RAM --| will behave similar as the following fake resource tree for region_intersects(, IORESOURCE_SYSTEM_RAM, ), |-- System RAM --||-- CXL Window 0a --| Where CXL Window 0a is part of the original CXL Window 0 that isn't covered by System RAM. (CVE-2024-49878)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://nvd.nist.gov/vuln/detail/CVE-2024-49878

Plugin Details

Severity: Medium

ID: 212843

File Name: mariner_CVE-2024-49878.nasl

Version: 1.1

Type: local

Published: 12/13/2024

Updated: 12/13/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C

CVSS Score Source: CVE-2024-49878

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:microsoft:cbl-mariner:python3-perf, p-cpe:/a:microsoft:cbl-mariner:kernel-devel, p-cpe:/a:microsoft:cbl-mariner:kernel-tools, p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-accessibility, p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-gpu, x-cpe:/o:microsoft:cbl-mariner, p-cpe:/a:microsoft:cbl-mariner:kernel, p-cpe:/a:microsoft:cbl-mariner:kernel-dtb, p-cpe:/a:microsoft:cbl-mariner:bpftool, p-cpe:/a:microsoft:cbl-mariner:kernel-docs, p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-sound

Required KB Items: Host/local_checks_enabled, Host/CBLMariner/release, Host/CBLMariner/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 12/10/2024

Vulnerability Publication Date: 10/21/2024

Reference Information

CVE: CVE-2024-49878