# CVE-2022-49476: mt76: mt7921: fix kernel crash at mt7921_pci_remove

> A race condition in the mt7921 PCI driver causes a kernel crash during device removal, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 26 Feb 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-49476, GHSA-h9m4-2235-4mrh, ROOT-OS-UBUNTU-2204-CVE-2022-49476, UBUNTU-CVE-2022-49476

## What is CVE-2022-49476?

CVE-2022-49476 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 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:

mt76: mt7921: fix kernel crash at mt7921_pci_remove

The crash log shown it is possible that mt7921_irq_handler is called while
devm_free_irq is being handled so mt76_free_device need to be postponed
until devm_free_irq is completed to solve the crash we free the mt76 device
too early.

[ 9299.339655] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 9299.339705] #PF: supervisor read access in kernel mode
[ 9299.339735] #PF: error_code(0x0000) - not-present page
[ 9299.339768] PGD 0 P4D 0
[ 9299.339786] Oops: 0000 [#1] SMP PTI
[ 9299.339812] CPU: 1 PID: 1624 Comm: prepare-suspend Not tainted 5.15.14-1.fc32.qubes.x86_64 #1
[ 9299.339863] Hardware name: Xen HVM domU, BIOS 4.14.3 01/20/2022
[ 9299.339901] RIP: 0010:mt7921_irq_handler+0x1e/0x70 [mt7921e]
[ 9299.340048] RSP: 0018:ffffa81b80c27cb0 EFLAGS: 00010082
[ 9299.340081] RAX: 0000000000000000 RBX: ffff98a4cb752020 RCX: ffffffffa96211c5
[ 9299.340123] RDX: 0000000000000000 RSI: 00000000000d4204 RDI: ffff98a4cb752020
[ 9299.340165] RBP: ffff98a4c28a62a4 R08: ffff98a4c37a96c0 R09: 0000000080150011
[ 9299.340207] R10: 0000000040000000 R11: 0000000000000000 R12: ffff98a4c4eaa080
[ 9299.340249] R13: ffff98a4c28a6360 R14: ffff98a4cb752020 R15: ffff98a4c28a6228
[ 9299.340297] FS: 00007260840d3740(0000) GS:ffff98a4ef700000(0000) knlGS:0000000000000000
[ 9299.340345] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9299.340383] CR2: 0000000000000008 CR3: 0000000004c56001 CR4: 0000000000770ee0
[ 9299.340432] PKRU: 55555554
[ 9299.340449] Call Trace:
[ 9299.340467] <TASK>
[ 9299.340485] __free_irq+0x221/0x350
[ 9299.340527] free_irq+0x30/0x70
[ 9299.340553] devm_free_irq+0x55/0x80
[ 9299.340579] mt7921_pci_remove+0x2f/0x40 [mt7921e]
[ 9299.340616] pci_device_remove+0x3b/0xa0
[ 9299.340651] __device_release_driver+0x17a/0x240
[ 9299.340686] device_driver_detach+0x3c/0xa0
[ 9299.340714] unbind_store+0x113/0x130
[ 9299.340740] kernfs_fop_write_iter+0x124/0x1b0
[ 9299.340775] new_sync_write+0x15c/0x1f0
[ 9299.340806] vfs_write+0x1d2/0x270
[ 9299.340831] ksys_write+0x67/0xe0
[ 9299.340857] do_syscall_64+0x3b/0x90
[ 9299.340887] entry_SYSCALL_64_after_hwframe+0x44/0xae

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-49476?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49476?

Apply the vendor's patch.

## Is CVE-2022-49476 being exploited?

There is no known exploitation of CVE-2022-49476 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-2022-49476 and fix it if it is affected.

What it is: CVE-2022-49476 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 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-2022-49476 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-2022-49476/ (Markdown: https://insights.sbomify.com/CVE-2022-49476/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49476
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49476
- OSV: https://osv.dev/vulnerability/CVE-2022-49476

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49476/
Summaries are generated and may contain mistakes; the official description above is the record.