# CVE-2025-22020: memstick: rtsx_usb_ms: Fix slab-use-after-free in rtsx_usb_ms_drv_remove

> A use-after-free vulnerability in the Linux kernel's rtsx_usb_ms driver allows a local attacker to cause a system crash via a race condition during device removal.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Apr 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-22020, DEBIAN-CVE-2025-22020, GHSA-h2g5-mxp5-qrcx, ROOT-OS-DEBIAN-12-CVE-2025-22020, ROOT-OS-UBUNTU-2404-CVE-2025-22020, UBUNTU-CVE-2025-22020

## What is CVE-2025-22020?

CVE-2025-22020 is a high-severity use after free vulnerability in Linux kernel, published on 16 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

memstick: rtsx_usb_ms: Fix slab-use-after-free in rtsx_usb_ms_drv_remove

This fixes the following crash:

==================================================================
BUG: KASAN: slab-use-after-free in rtsx_usb_ms_poll_card+0x159/0x200 [rtsx_usb_ms]
Read of size 8 at addr ffff888136335380 by task kworker/6:0/140241

CPU: 6 UID: 0 PID: 140241 Comm: kworker/6:0 Kdump: loaded Tainted: G            E      6.14.0-rc6+ #1
Tainted: [E]=UNSIGNED_MODULE
Hardware name: LENOVO 30FNA1V7CW/1057, BIOS S0EKT54A 07/01/2024
Workqueue: events rtsx_usb_ms_poll_card [rtsx_usb_ms]
Call Trace:
 <TASK>
 dump_stack_lvl+0x51/0x70
 print_address_description.constprop.0+0x27/0x320
 ? rtsx_usb_ms_poll_card+0x159/0x200 [rtsx_usb_ms]
 print_report+0x3e/0x70
 kasan_report+0xab/0xe0
 ? rtsx_usb_ms_poll_card+0x159/0x200 [rtsx_usb_ms]
 rtsx_usb_ms_poll_card+0x159/0x200 [rtsx_usb_ms]
 ? __pfx_rtsx_usb_ms_poll_card+0x10/0x10 [rtsx_usb_ms]
 ? __pfx___schedule+0x10/0x10
 ? kick_pool+0x3b/0x270
 process_one_work+0x357/0x660
 worker_thread+0x390/0x4c0
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x190/0x1d0
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x2d/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 161446:
 kasan_save_stack+0x20/0x40
 kasan_save_track+0x10/0x30
 __kasan_kmalloc+0x7b/0x90
 __kmalloc_noprof+0x1a7/0x470
 memstick_alloc_host+0x1f/0xe0 [memstick]
 rtsx_usb_ms_drv_probe+0x47/0x320 [rtsx_usb_ms]
 platform_probe+0x60/0xe0
 call_driver_probe+0x35/0x120
 really_probe+0x123/0x410
 __driver_probe_device+0xc7/0x1e0
 driver_probe_device+0x49/0xf0
 __device_attach_driver+0xc6/0x160
 bus_for_each_drv+0xe4/0x160
 __device_attach+0x13a/0x2b0
 bus_probe_device+0xbd/0xd0
 device_add+0x4a5/0x760
 platform_device_add+0x189/0x370
 mfd_add_device+0x587/0x5e0
 mfd_add_devices+0xb1/0x130
 rtsx_usb_probe+0x28e/0x2e0 [rtsx_usb]
 usb_probe_interface+0x15c/0x460
 call_driver_probe+0x35/0x120
 really_probe+0x123/0x410
 __driver_probe_device+0xc7/0x1e0
 driver_probe_device+0x49/0xf0
 __device_attach_driver+0xc6/0x160
 bus_for_each_drv+0xe4/0x160
 __device_attach+0x13a/0x2b0
 rebind_marked_interfaces.isra.0+0xcc/0x110
 usb_reset_device+0x352/0x410
 usbdev_do_ioctl+0xe5c/0x1860
 usbdev_ioctl+0xa/0x20
 __x64_sys_ioctl+0xc5/0xf0
 do_syscall_64+0x59/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 161506:
 kasan_save_stack+0x20/0x40
 kasan_save_track+0x10/0x30
 kasan_save_free_info+0x36/0x60
 __kasan_slab_free+0x34/0x50
 kfree+0x1fd/0x3b0
 device_release+0x56/0xf0
 kobject_cleanup+0x73/0x1c0
 rtsx_usb_ms_drv_remove+0x13d/0x220 [rtsx_usb_ms]
 platform_remove+0x2f/0x50
 device_release_driver_internal+0x24b/0x2e0
 bus_remove_device+0x124/0x1d0
 device_del+0x239/0x530
 platform_device_del.part.0+0x19/0xe0
 platform_device_unregister+0x1c/0x40
 mfd_remove_devices_fn+0x167/0x170
 device_for_each_child_reverse+0xc9/0x130
 mfd_remove_devices+0x6e/0xa0
 rtsx_usb_disconnect+0x2e/0xd0 [rtsx_usb]
 usb_unbind_interface+0xf3/0x3f0
 device_release_driver_internal+0x24b/0x2e0
 proc_disconnect_claim+0x13d/0x220
 usbdev_do_ioctl+0xb5e/0x1860
 usbdev_ioctl+0xa/0x20
 __x64_sys_ioctl+0xc5/0xf0
 do_syscall_64+0x59/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Last potentially related work creation:
 kasan_save_stack+0x20/0x40
 kasan_record_aux_stack+0x85/0x90
 insert_work+0x29/0x100
 __queue_work+0x34a/0x540
 call_timer_fn+0x2a/0x160
 expire_timers+0x5f/0x1f0
 __run_timer_base.part.0+0x1b6/0x1e0
 run_timer_softirq+0x8b/0xe0
 handle_softirqs+0xf9/0x360
 __irq_exit_rcu+0x114/0x130
 sysvec_apic_timer_interrupt+0x72/0x90
 asm_sysvec_apic_timer_interrupt+0x16/0x20

Second to last potentially related work creation:
 kasan_save_stack+0x20/0x40
 kasan_record_aux_stack+0x85/0x90
 insert_work+0x29/0x100
 __queue_work+0x34a/0x540
 call_timer_fn+0x2a/0x160
 expire_timers+0x5f/0x1f0
 __run_timer_base.part.0+0x1b6/0x1e0
 run_timer_softirq+0x8b/0xe0
 handle_softirqs+0xf9/0x
---truncated---

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-22020?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-22020?

Apply the vendor's patch.

## Is CVE-2025-22020 being exploited?

There is no known exploitation of CVE-2025-22020 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-22020 and fix it if it is affected.

What it is: CVE-2025-22020 is a high-severity use after free vulnerability in Linux kernel, published on 16 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-22020 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-22020/ (Markdown: https://insights.sbomify.com/CVE-2025-22020/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-22020
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-22020
- OSV: https://osv.dev/vulnerability/CVE-2025-22020

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-22020/
Summaries are generated and may contain mistakes; the official description above is the record.