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.
Metrics
Affected Vendors & Products
Tue, 05 Nov 2024 08:15:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
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Wed, 18 Sep 2024 18:15:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
Vendors & Products |
Linux
Linux linux Kernel |
|
Metrics |
cvssV3_1
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cvssV3_1
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Thu, 12 Sep 2024 20:30:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
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Wed, 11 Sep 2024 13:30:00 +0000
Type | Values Removed | Values Added |
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Metrics |
ssvc
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:15:02.390Z
Reserved: 2024-06-19T14:55:32.795Z
Link: CVE-2021-47617

Updated: 2024-08-04T05:47:40.879Z

Status : Modified
Published: 2024-06-20T11:15:54.317
Modified: 2024-11-21T06:36:40.810
Link: CVE-2021-47617


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