Bug 2425198 (CVE-2022-50744)

Summary:	CVE-2022-50744 kernel: Linux kernel: Hard lockup in lpfc driver leads to Denial of Service
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel. A local user could trigger a hard lockup by concurrently reading the `rx_monitor` from `debugfs` during I/O operations in the `lpfc` driver. This concurrency issue, caused by insufficient spin lock protection, leads to a system crash and results in a Denial of Service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-12-24 14:10:14 UTC

In the Linux kernel, the following vulnerability has been resolved:

scsi: lpfc: Fix hard lockup when reading the rx_monitor from debugfs

During I/O and simultaneous cat of /sys/kernel/debug/lpfc/fnX/rx_monitor, a
hard lockup similar to the call trace below may occur.

The spin_lock_bh in lpfc_rx_monitor_report is not protecting from timer
interrupts as expected, so change the strength of the spin lock to _irq.

Kernel panic - not syncing: Hard LOCKUP
CPU: 3 PID: 110402 Comm: cat Kdump: loaded

exception RIP: native_queued_spin_lock_slowpath+91

[IRQ stack]
 native_queued_spin_lock_slowpath at ffffffffb814e30b
 _raw_spin_lock at ffffffffb89a667a
 lpfc_rx_monitor_record at ffffffffc0a73a36 [lpfc]
 lpfc_cmf_timer at ffffffffc0abbc67 [lpfc]
 __hrtimer_run_queues at ffffffffb8184250
 hrtimer_interrupt at ffffffffb8184ab0
 smp_apic_timer_interrupt at ffffffffb8a026ba
 apic_timer_interrupt at ffffffffb8a01c4f
[End of IRQ stack]

 apic_timer_interrupt at ffffffffb8a01c4f
 lpfc_rx_monitor_report at ffffffffc0a73c80 [lpfc]
 lpfc_rx_monitor_read at ffffffffc0addde1 [lpfc]
 full_proxy_read at ffffffffb83e7fc3
 vfs_read at ffffffffb833fe71
 ksys_read at ffffffffb83402af
 do_syscall_64 at ffffffffb800430b
 entry_SYSCALL_64_after_hwframe at ffffffffb8a000ad

Comment 1 Alexander B 2025-12-24 19:20:36 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122449-CVE-2022-50744-bc80@gregkh/T