CVE-2021-47617

Medium

In the Linux kernel, the following vulnerability has been resolved: PCI: pciehp: Fix infinite loop in IRQ handler upon power fault The Power Fault Detected bit in the Slot Status register differs from all other hotplug events in that it is sticky: It can only be cleared after turning off slot power. Per PCIe r5.0, sec. 6.7.1.8: If a power controller detects a main power fault on the hot-plug slot, it must automatically set its internal main power fault latch [...]. The main power fault latch is cleared when software turns off power to the hot-plug slot. The stickiness used to cause interrupt storms and infinite loops which were fixed in 2009 by commits 5651c48cfafe ("PCI pciehp: fix power fault interrupt storm problem") and 99f0169c17f3 ("PCI: pciehp: enable software notification on empty slots"). Unfortunately in 2020 the infinite loop issue was inadvertently reintroduced by commit 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt race"): The hardirq handler pciehp_isr() clears the PFD bit until pciehp's power_fault_detected flag is set. That happens in the IRQ thread pciehp_ist(), which never learns of the event because the hardirq handler is stuck in an infinite loop. Fix by setting the power_fault_detected flag already in the hardirq handler.

Package Linux Kernel
Published 2024-06-20
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-835

CVE-2021-47617 is a Infinite Loop vulnerability

What is Infinite Loop?

The product contains an iteration that does not exit even when it should. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.19.149, 5.4.69, 5.7 and later are affected. Fixed in 4.19.233, 5.4.177, 5.10.97, 5.15.20, 5.16.6, 5.17 and their respective stable series.

Affected from
≥ 4.19.149 ≥ 5.4.69 ≥ 5.7
Fixed in
✓ 4.19.233 4.19.x ✓ 5.4.177 5.4.x ✓ 5.10.97 5.10.x ✓ 5.15.20 5.15.x ✓ 5.16.6 5.16.x ✓ 5.17

References

6 total
Showing 5 of 6 references View all on NVD

Frequently asked questions

  • What is CVE-2021-47617?

    CVE-2021-47617 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as an Infinite Loop flaw (CWE-835) . It affects Linux kernel versions from 4.19.149 onward and has been patched in 4.19.233, 5.4.177, 5.10.97 and others. CVE-2021-47617 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47617?

    CVE-2021-47617 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-2021-47617?

    Yes. CVE-2021-47617 has been patched. Fixed versions include 4.19.233, 5.4.177, 5.10.97 and others. If you are running Linux kernel 4.19.149 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2021-47617 actively exploited?

    No. CVE-2021-47617 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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