CVE-2021-47542

Medium

In the Linux kernel, the following vulnerability has been resolved: net: qlogic: qlcnic: Fix a NULL pointer dereference in qlcnic_83xx_add_rings() In qlcnic_83xx_add_rings(), the indirect function of ahw->hw_ops->alloc_mbx_args will be called to allocate memory for cmd.req.arg, and there is a dereference of it in qlcnic_83xx_add_rings(), which could lead to a NULL pointer dereference on failure of the indirect function like qlcnic_83xx_alloc_mbx_args(). Fix this bug by adding a check of alloc_mbx_args(), this patch imitates the logic of mbx_cmd()'s failure handling. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_QLCNIC=m show no new warnings, and our static analyzer no longer warns about this code.

Package Linux Kernel
Published 2024-05-24
Last modified 2024-11-21
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2021-47542 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 3.9 and later are affected. Fixed in 4.4.294, 4.9.292, 4.14.257, 4.19.220, 5.4.164, 5.10.84, 5.15.7, 5.16 and their respective stable series.

Affected from
≥ 3.9
Fixed in
✓ 4.4.294 4.4.x ✓ 4.9.292 4.9.x ✓ 4.14.257 4.14.x ✓ 4.19.220 4.19.x ✓ 5.4.164 5.4.x ✓ 5.10.84 5.10.x ✓ 5.15.7 5.15.x ✓ 5.16

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2021-47542?

    CVE-2021-47542 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 3.9 onward and has been patched in 4.4.294, 4.9.292, 4.14.257 and others. CVE-2021-47542 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47542?

    CVE-2021-47542 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2021-47542?

    Yes. CVE-2021-47542 has been patched. Fixed versions include 4.4.294, 4.9.292, 4.14.257 and others. If you are running Linux kernel 3.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2021-47542 actively exploited?

    No. CVE-2021-47542 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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