CVE-2022-49010
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: hwmon: (coretemp) Check for null before removing sysfs attrs If coretemp_add_core() gets an error then pdata->core_data[indx] is already NULL and has been kfreed. Don't pass that to sysfs_remove_group() as that will crash in sysfs_remove_group(). [Shortened for readability] [91854.020159] sysfs: cannot create duplicate filename '/devices/platform/coretemp.0/hwmon/hwmon2/temp20_label' <cpu offline> [91855.126115] BUG: kernel NULL pointer dereference, address: 0000000000000188 [91855.165103] #PF: supervisor read access in kernel mode [91855.194506] #PF: error_code(0x0000) - not-present page [91855.224445] PGD 0 P4D 0 [91855.238508] Oops: 0000 [#1] PREEMPT SMP PTI ... [91855.342716] RIP: 0010:sysfs_remove_group+0xc/0x80 ... [91855.796571] Call Trace: [91855.810524] coretemp_cpu_offline+0x12b/0x1dd [coretemp] [91855.841738] ? coretemp_cpu_online+0x180/0x180 [coretemp] [91855.871107] cpuhp_invoke_callback+0x105/0x4b0 [91855.893432] cpuhp_thread_fun+0x8e/0x150 ... Fix this by checking for NULL first.
Statement
This issue is fixed in RHEL-9.2 and above (including RHEL 8.10)
f1215e1da161 (in rhel-9.2, rhel-9.3, rhel-9.4, rhel-9.5, rhel-9.6) hwmon: (coretemp) Check for null before removing sysfs attrs
5e2e2086e01a (in rhel-8.8, rhel-8.9, rhel-8.10) hwmon: (coretemp) Check for null before removing sysfs attrs
Please note that while RHEL-9 kernel-rt still appears as affected, it has been fixed in the same RHSA as RHEL-9 kernel. This is because from RHEL-9.3 onwards, the kernel and kernel-rt fixes are bundled together in a single errata.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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