# CVE-2022-50652: uio: uio_dmem_genirq: Fix missing unlock in irq configuration

> A local attacker can cause a kernel panic and system crash by repeatedly writing to a specific UIO device file due to a missing spinlock unlock.

- **Severity:** Not scored
- **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:** 9 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** DEBIAN-CVE-2022-50652, GHSA-7863-hf67-mmwv, UBUNTU-CVE-2022-50652

## What is CVE-2022-50652?

CVE-2022-50652 is a denial of service vulnerability in Linux, published on 9 Dec 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:

uio: uio_dmem_genirq: Fix missing unlock in irq configuration

Commit b74351287d4b ("uio: fix a sleep-in-atomic-context bug in
uio_dmem_genirq_irqcontrol()") started calling disable_irq() without
holding the spinlock because it can sleep. However, that fix introduced
another bug: if interrupt is already disabled and a new disable request
comes in, then the spinlock is not unlocked:

root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0
root@localhost:~# printf '\x00\x00\x00\x00' > /dev/uio0
root@localhost:~# [   14.851538] BUG: scheduling while atomic: bash/223/0x00000002
[   14.851991] Modules linked in: uio_dmem_genirq uio myfpga(OE) bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper drm snd_pcm ppdev joydev psmouse snd_timer snd e1000fb_sys_fops syscopyarea parport sysfillrect soundcore sysimgblt input_leds pcspkr i2c_piix4 serio_raw floppy evbug qemu_fw_cfg mac_hid pata_acpi ip_tables x_tables autofs4 [last unloaded: parport_pc]
[   14.854206] CPU: 0 PID: 223 Comm: bash Tainted: G           OE      6.0.0-rc7 #21
[   14.854786] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[   14.855664] Call Trace:
[   14.855861]  <TASK>
[   14.856025]  dump_stack_lvl+0x4d/0x67
[   14.856325]  dump_stack+0x14/0x1a
[   14.856583]  __schedule_bug.cold+0x4b/0x5c
[   14.856915]  __schedule+0xe81/0x13d0
[   14.857199]  ? idr_find+0x13/0x20
[   14.857456]  ? get_work_pool+0x2d/0x50
[   14.857756]  ? __flush_work+0x233/0x280
[   14.858068]  ? __schedule+0xa95/0x13d0
[   14.858307]  ? idr_find+0x13/0x20
[   14.858519]  ? get_work_pool+0x2d/0x50
[   14.858798]  schedule+0x6c/0x100
[   14.859009]  schedule_hrtimeout_range_clock+0xff/0x110
[   14.859335]  ? tty_write_room+0x1f/0x30
[   14.859598]  ? n_tty_poll+0x1ec/0x220
[   14.859830]  ? tty_ldisc_deref+0x1a/0x20
[   14.860090]  schedule_hrtimeout_range+0x17/0x20
[   14.860373]  do_select+0x596/0x840
[   14.860627]  ? __kernel_text_address+0x16/0x50
[   14.860954]  ? poll_freewait+0xb0/0xb0
[   14.861235]  ? poll_freewait+0xb0/0xb0
[   14.861517]  ? rpm_resume+0x49d/0x780
[   14.861798]  ? common_interrupt+0x59/0xa0
[   14.862127]  ? asm_common_interrupt+0x2b/0x40
[   14.862511]  ? __uart_start.isra.0+0x61/0x70
[   14.862902]  ? __check_object_size+0x61/0x280
[   14.863255]  core_sys_select+0x1c6/0x400
[   14.863575]  ? vfs_write+0x1c9/0x3d0
[   14.863853]  ? vfs_write+0x1c9/0x3d0
[   14.864121]  ? _copy_from_user+0x45/0x70
[   14.864526]  do_pselect.constprop.0+0xb3/0xf0
[   14.864893]  ? do_syscall_64+0x6d/0x90
[   14.865228]  ? do_syscall_64+0x6d/0x90
[   14.865556]  __x64_sys_pselect6+0x76/0xa0
[   14.865906]  do_syscall_64+0x60/0x90
[   14.866214]  ? syscall_exit_to_user_mode+0x2a/0x50
[   14.866640]  ? do_syscall_64+0x6d/0x90
[   14.866972]  ? do_syscall_64+0x6d/0x90
[   14.867286]  ? do_syscall_64+0x6d/0x90
[   14.867626]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...] stripped
[   14.872959]  </TASK>

('myfpga' is a simple 'uio_dmem_genirq' driver I wrote to test this)

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
introduced, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(). Then commit 34cb27528398 ("UIO: Fix concurrency
issue"), which was only applied to "uio_pdrv_genirq", ended up making them
a little different. That commit, among other things, changed disable_irq()
to disable_irq_nosync() in the implementation of irqcontrol(). The
motivation there was to avoid a deadlock between irqcontrol() and
handler(), since it added a spinlock in the irq handler, and disable_irq()
waits for the completion of the irq handler.

By changing disable_irq() to disable_irq_nosync() in irqcontrol(), we also
avoid the sleeping-whil
---truncated---

## Which versions are affected by CVE-2022-50652?


## How do I fix CVE-2022-50652?

Apply the vendor's patch.

## Is CVE-2022-50652 being exploited?

There is no known exploitation of CVE-2022-50652 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50652 and fix it if it is affected.

What it is: CVE-2022-50652 is a denial of service vulnerability in Linux, published on 9 Dec 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-2022-50652 in the wild and no public exploit code.

Affected product: Linux. 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-2022-50652/ (Markdown: https://insights.sbomify.com/CVE-2022-50652/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50652
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50652
- OSV: https://osv.dev/vulnerability/CVE-2022-50652

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50652/
Summaries are generated and may contain mistakes; the official description above is the record.
