CVE-2024-36950

firewire: ohci: mask bus reset interrupts between ISR and bottom half

Published May 30, 2024 CVSS 3.1 · 4.4 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

firewire: ohci: mask bus reset interrupts between ISR and bottom half

In the FireWire OHCI interrupt handler, if a bus reset interrupt has
occurred, mask bus reset interrupts until bus_reset_work has serviced and
cleared the interrupt.

Normally, we always leave bus reset interrupts masked. We infer the bus
reset from the self-ID interrupt that happens shortly thereafter. A
scenario where we unmask bus reset interrupts was introduced in 2008 in
a007bb857e0b26f5d8b73c2ff90782d9c0972620: If
OHCI_PARAM_DEBUG_BUSRESETS (8) is set in the debug parameter bitmask, we
will unmask bus reset interrupts so we can log them.

irq_handler logs the bus reset interrupt. However, we can't clear the bus
reset event flag in irq_handler, because we won't service the event until
later. irq_handler exits with the event flag still set. If the
corresponding interrupt is still unmasked, the first bus reset will
usually freeze the system due to irq_handler being called again each
time it exits. This freeze can be reproduced by loading firewire_ohci
with "modprobe firewire_ohci debug=-1" (to enable all debugging output).
Apparently there are also some cases where bus_reset_work will get called
soon enough to clear the event, and operation will continue normally.

This freeze was first reported a few months after a007bb85 was committed,
but until now it was never fixed. The debug level could safely be set
to -1 through sysfs after the module was loaded, but this would be
ineffectual in logging bus reset interrupts since they were only
unmasked during initialization.

irq_handler will now leave the event flag set but mask bus reset
interrupts, so irq_handler won't be called again and there will be no
freeze. If OHCI_PARAM_DEBUG_BUSRESETS is enabled, bus_reset_work will
unmask the interrupt after servicing the event, so future interrupts
will be caught as desired.

As a side effect to this change, OHCI_PARAM_DEBUG_BUSRESETS can now be
enabled through sysfs in addition to during initial module loading.
However, when enabled through sysfs, logging of bus reset interrupts will
be effective only starting with the second bus reset, after
bus_reset_work has executed.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Debian DLA Debian DLA DLA-3840-1 linux security update
Debian DLA Debian DLA DLA-3843-1 linux-5.10 security update
Debian DSA Debian DSA DSA-5703-1 linux security update
Ubuntu USN Ubuntu USN USN-6949-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6949-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6950-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6950-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6950-3 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6950-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6951-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6951-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6951-3 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6951-4 Linux kernel (BlueField) vulnerabilities
Ubuntu USN Ubuntu USN USN-6952-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6953-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6955-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6956-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6957-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6979-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7019-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Linux
Linux linux Kernel
Type Values Removed Values Added
Metrics epss

{'score': 0.00015}

epss

{'score': 0.00017}

Type Values Removed Values Added
Metrics epss

{'score': 0.00016}

epss

{'score': 0.00015}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:8::nfv
cpe:/o:redhat:enterprise_linux:8
Vendors & Products Redhat
Redhat enterprise Linux
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:17 PM
Reserved
May 30, 2024, 3:25 PM
Status
Analyzed
Published
May 30, 2024, 4:15 PM
Modified
Jun 17, 2026, 7:37 AM
Severity
Low
Public date
May 30, 2024, 12:00 AM