Upstream information

CVE-2025-39996 at MITRE

Description

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

media: b2c2: Fix use-after-free causing by irq_check_work in flexcop_pci_remove

The original code uses cancel_delayed_work() in flexcop_pci_remove(), which
does not guarantee that the delayed work item irq_check_work has fully
completed if it was already running. This leads to use-after-free scenarios
where flexcop_pci_remove() may free the flexcop_device while irq_check_work
is still active and attempts to dereference the device.

A typical race condition is illustrated below:

CPU 0 (remove) | CPU 1 (delayed work callback)
flexcop_pci_remove() | flexcop_pci_irq_check_work()
cancel_delayed_work() |
flexcop_device_kfree(fc_pci->fc_dev) |
| fc = fc_pci->fc_dev; // UAF

This is confirmed by a KASAN report:

==================================================================
BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0
Write of size 8 at addr ffff8880093aa8c8 by task bash/135
...
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_report+0xcf/0x610
? __run_timer_base.part.0+0x7d7/0x8c0
kasan_report+0xb8/0xf0
? __run_timer_base.part.0+0x7d7/0x8c0
__run_timer_base.part.0+0x7d7/0x8c0
? __pfx___run_timer_base.part.0+0x10/0x10
? __pfx_read_tsc+0x10/0x10
? ktime_get+0x60/0x140
? lapic_next_event+0x11/0x20
? clockevents_program_event+0x1d4/0x2a0
run_timer_softirq+0xd1/0x190
handle_softirqs+0x16a/0x550
irq_exit_rcu+0xaf/0xe0
sysvec_apic_timer_interrupt+0x70/0x80
</IRQ>
...

Allocated by task 1:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x7f/0x90
__kmalloc_noprof+0x1be/0x460
flexcop_device_kmalloc+0x54/0xe0
flexcop_pci_probe+0x1f/0x9d0
local_pci_probe+0xdc/0x190
pci_device_probe+0x2fe/0x470
really_probe+0x1ca/0x5c0
__driver_probe_device+0x248/0x310
driver_probe_device+0x44/0x120
__driver_attach+0xd2/0x310
bus_for_each_dev+0xed/0x170
bus_add_driver+0x208/0x500
driver_register+0x132/0x460
do_one_initcall+0x89/0x300
kernel_init_freeable+0x40d/0x720
kernel_init+0x1a/0x150
ret_from_fork+0x10c/0x1a0
ret_from_fork_asm+0x1a/0x30

Freed by task 135:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3a/0x60
__kasan_slab_free+0x3f/0x50
kfree+0x137/0x370
flexcop_device_kfree+0x32/0x50
pci_device_remove+0xa6/0x1d0
device_release_driver_internal+0xf8/0x210
pci_stop_bus_device+0x105/0x150
pci_stop_and_remove_bus_device_locked+0x15/0x30
remove_store+0xcc/0xe0
kernfs_fop_write_iter+0x2c3/0x440
vfs_write+0x871/0xd70
ksys_write+0xee/0x1c0
do_syscall_64+0xac/0x280
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...

Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the delayed work item is properly canceled and any executing delayed
work has finished before the device memory is deallocated.

This bug was initially identified through static analysis. To reproduce
and test it, I simulated the B2C2 FlexCop PCI device in QEMU and introduced
artificial delays within the flexcop_pci_irq_check_work() function to
increase the likelihood of triggering the bug.

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having moderate severity.

CVSS v3 Scores
CVSS detail SUSE
Base Score 5.5
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
CVSSv3 Version 3.1

Note from the SUSE Security Team on the kernel-default package

SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details.

SUSE Bugzilla entry: 1252065 [NEW]

No SUSE Security Announcements cross referenced.


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Desktop 15 SP6 kernel-default Affected
SUSE Linux Enterprise Desktop 15 SP6 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP7 kernel-default Affected
SUSE Linux Enterprise Desktop 15 SP7 kernel-source Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-default Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source-azure Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-source-azure Affected
SUSE Linux Enterprise Live Patching 15 SP6 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP6 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP7 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP7 kernel-source Affected
SUSE Linux Enterprise Micro 5.1 kernel-default Affected
SUSE Linux Enterprise Micro 5.1 kernel-rt Affected
SUSE Linux Enterprise Micro 5.1 kernel-source Affected
SUSE Linux Enterprise Micro 5.1 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.2 kernel-default Affected
SUSE Linux Enterprise Micro 5.2 kernel-rt Affected
SUSE Linux Enterprise Micro 5.2 kernel-source Affected
SUSE Linux Enterprise Micro 5.2 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.3 kernel-default Affected
SUSE Linux Enterprise Micro 5.3 kernel-rt Affected
SUSE Linux Enterprise Micro 5.3 kernel-source Affected
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-default Affected
SUSE Linux Enterprise Micro 5.4 kernel-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-source Affected
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.5 kernel-default Affected
SUSE Linux Enterprise Micro 5.5 kernel-source Affected
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-default Affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-default Affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-source Affected
SUSE Linux Enterprise Module for Legacy 15 SP6 kernel-default Affected
SUSE Linux Enterprise Module for Legacy 15 SP6 kernel-source Affected
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-source Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-source-azure Affected
SUSE Linux Enterprise Real Time 15 SP6 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP7 kernel-source-rt Affected
SUSE Linux Enterprise Server 15 SP6 kernel-default Affected
SUSE Linux Enterprise Server 15 SP6 kernel-source Affected
SUSE Linux Enterprise Server 15 SP6 kernel-source-azure Affected
SUSE Linux Enterprise Server 15 SP7 kernel-default Affected
SUSE Linux Enterprise Server 15 SP7 kernel-source Affected
SUSE Linux Enterprise Server 15 SP7 kernel-source-azure Affected
SUSE Linux Enterprise Server 16.0 kernel-default Affected
SUSE Linux Enterprise Server 16.0 kernel-source Affected
SUSE Linux Enterprise Server 16.0 kernel-source-azure Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source-azure Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-source-azure Affected
SUSE Linux Enterprise Server for SAP Applications 16.0 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 16.0 kernel-source-azure Affected
SUSE Linux Enterprise Workstation Extension 15 SP6 kernel-default Affected
SUSE Linux Enterprise Workstation Extension 15 SP6 kernel-source Affected
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-default Affected
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-source Affected
SUSE Linux Micro 6.0 kernel-default Affected
SUSE Linux Micro 6.0 kernel-source Affected
SUSE Linux Micro 6.0 kernel-source-rt Affected
SUSE Linux Micro 6.1 kernel-default Affected
SUSE Linux Micro 6.1 kernel-source Affected
SUSE Linux Micro 6.1 kernel-source-rt Affected
SUSE Linux Micro 6.2 kernel-source Affected
SUSE Real Time Module 15 SP6 kernel-source-rt Affected
SUSE Real Time Module 15 SP7 kernel-source-rt Affected
openSUSE Leap 15.6 kernel-default Affected
openSUSE Leap 15.6 kernel-source Affected
openSUSE Leap 15.6 kernel-source-azure Affected
openSUSE Leap 15.6 kernel-source-rt Affected
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP3 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP3 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Affected
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default Affected
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source Affected
SUSE Linux Enterprise Server 12 SP5 kernel-source Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-default Affected
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-source Affected
SUSE Linux Enterprise Server 15 SP3 kernel-source Affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP5 kernel-source Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source Affected
SUSE Manager Proxy 4.3 kernel-source Affected
SUSE Manager Proxy LTS 4.3 kernel-default Affected
SUSE Manager Proxy LTS 4.3 kernel-source Affected
SUSE Manager Retail Branch Server 4.3 kernel-source Affected
SUSE Manager Retail Branch Server LTS 4.3 kernel-default Affected
SUSE Manager Retail Branch Server LTS 4.3 kernel-source Affected
SUSE Manager Server 4.3 kernel-source Affected
SUSE Manager Server LTS 4.3 kernel-default Affected
SUSE Manager Server LTS 4.3 kernel-source Affected
Products past their end of life and not receiving proactive updates anymore.
SUSE CaaS Platform 4.0 kernel-source Affected
SUSE Enterprise Storage 6 kernel-source Affected
SUSE Enterprise Storage 7 kernel-source Affected
SUSE Enterprise Storage 7.1 kernel-source Affected
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Affected
SUSE Linux Enterprise Desktop 12 SP2 kernel-source Affected
SUSE Linux Enterprise Desktop 12 SP4 kernel-source Affected
SUSE Linux Enterprise Desktop 15 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP4 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15-LTSS kernel-source Affected
SUSE Linux Enterprise Micro 5.0 kernel-default Affected
SUSE Linux Enterprise Module for Basesystem 15 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Affected
SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP3 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Affected
SUSE Linux Enterprise Server 11 SP4 kernel-source Affected
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-default Affected
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-source Affected
SUSE Linux Enterprise Server 11 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 12 SP2 kernel-source Affected
SUSE Linux Enterprise Server 12 SP2-BCL kernel-source Affected
SUSE Linux Enterprise Server 12 SP2-ESPOS kernel-source Affected
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise Server 12 SP4 kernel-source Affected
SUSE Linux Enterprise Server 12 SP4-ESPOS kernel-source Affected
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 kernel-source Affected
SUSE Linux Enterprise Server 15 SP1 kernel-source Affected
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP2 kernel-source Affected
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Affected
SUSE Linux Enterprise Server 15-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15-LTSS kernel-source Affected
SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Affected
SUSE Manager Proxy 4.0 kernel-source Affected
SUSE Manager Proxy 4.1 kernel-source Affected
SUSE Manager Proxy 4.2 kernel-source Affected
SUSE Manager Retail Branch Server 4.0 kernel-source Affected
SUSE Manager Retail Branch Server 4.1 kernel-source Affected
SUSE Manager Retail Branch Server 4.2 kernel-source Affected
SUSE Manager Server 4.0 kernel-source Affected
SUSE Manager Server 4.1 kernel-source Affected
SUSE Manager Server 4.2 kernel-source Affected
SUSE OpenStack Cloud 7 kernel-source Affected
SUSE OpenStack Cloud 9 kernel-source Affected
SUSE OpenStack Cloud Crowbar 9 kernel-source Affected
SUSE Real Time Module 15 SP3 kernel-source-rt Affected
SUSE Real Time Module 15 SP4 kernel-source-rt Affected
SUSE Real Time Module 15 SP5 kernel-source-rt Affected
openSUSE Leap 15.3 kernel-source Affected
openSUSE Leap 15.3 kernel-source-rt Affected
openSUSE Leap 15.4 kernel-source Affected
openSUSE Leap 15.4 kernel-source-rt Affected
openSUSE Leap 15.5 kernel-source Affected
openSUSE Leap 15.5 kernel-source-rt Affected


SUSE Timeline for this CVE

CVE page created: Wed Oct 15 12:00:36 2025
CVE page last modified: Thu Oct 16 23:30:16 2025