# CVE-2022-50551: wifi: brcmfmac: Fix potential shift-out-of-bounds in brcmf_fw_alloc_request()

> A shift-out-of-bounds vulnerability in the Linux kernel brcmfmac WiFi driver allows a local attacker to cause a denial of service via a crafted device response.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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:** 7 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50551, GHSA-3cj2-mw4r-3p6w, ROOT-OS-UBUNTU-2204-CVE-2022-50551, ROOT-OS-UBUNTU-2404-CVE-2022-50551, UBUNTU-CVE-2022-50551

## What is CVE-2022-50551?

CVE-2022-50551 is a high-severity vulnerability in Linux kernel, published on 7 Oct 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:

wifi: brcmfmac: Fix potential shift-out-of-bounds in brcmf_fw_alloc_request()

This patch fixes a shift-out-of-bounds in brcmfmac that occurs in
BIT(chiprev) when a 'chiprev' provided by the device is too large.
It should also not be equal to or greater than BITS_PER_TYPE(u32)
as we do bitwise AND with a u32 variable and BIT(chiprev). The patch
adds a check that makes the function return NULL if that is the case.
Note that the NULL case is later handled by the bus-specific caller,
brcmf_usb_probe_cb() or brcmf_usb_reset_resume(), for example.

Found by a modified version of syzkaller.

UBSAN: shift-out-of-bounds in drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
shift exponent 151055786 is too large for 64-bit type 'long unsigned int'
CPU: 0 PID: 1885 Comm: kworker/0:2 Tainted: G           O      5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: usb_hub_wq hub_event
Call Trace:
 dump_stack_lvl+0x57/0x7d
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_shift_out_of_bounds.cold+0x53/0xdb
 ? lock_chain_count+0x20/0x20
 brcmf_fw_alloc_request.cold+0x19/0x3ea
 ? brcmf_fw_get_firmwares+0x250/0x250
 ? brcmf_usb_ioctl_resp_wait+0x1a7/0x1f0
 brcmf_usb_get_fwname+0x114/0x1a0
 ? brcmf_usb_reset_resume+0x120/0x120
 ? number+0x6c4/0x9a0
 brcmf_c_process_clm_blob+0x168/0x590
 ? put_dec+0x90/0x90
 ? enable_ptr_key_workfn+0x20/0x20
 ? brcmf_common_pd_remove+0x50/0x50
 ? rcu_read_lock_sched_held+0xa1/0xd0
 brcmf_c_preinit_dcmds+0x673/0xc40
 ? brcmf_c_set_joinpref_default+0x100/0x100
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lock_acquire+0x19d/0x4e0
 ? find_held_lock+0x2d/0x110
 ? brcmf_usb_deq+0x1cc/0x260
 ? mark_held_locks+0x9f/0xe0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 ? _raw_spin_unlock_irqrestore+0x47/0x50
 ? trace_hardirqs_on+0x1c/0x120
 ? brcmf_usb_deq+0x1a7/0x260
 ? brcmf_usb_rx_fill_all+0x5a/0xf0
 brcmf_attach+0x246/0xd40
 ? wiphy_new_nm+0x1476/0x1d50
 ? kmemdup+0x30/0x40
 brcmf_usb_probe+0x12de/0x1690
 ? brcmf_usbdev_qinit.constprop.0+0x470/0x470
 usb_probe_interface+0x25f/0x710
 really_probe+0x1be/0xa90
 __driver_probe_device+0x2ab/0x460
 ? usb_match_id.part.0+0x88/0xc0
 driver_probe_device+0x49/0x120
 __device_attach_driver+0x18a/0x250
 ? driver_allows_async_probing+0x120/0x120
 bus_for_each_drv+0x123/0x1a0
 ? bus_rescan_devices+0x20/0x20
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 ? trace_hardirqs_on+0x1c/0x120
 __device_attach+0x207/0x330
 ? device_bind_driver+0xb0/0xb0
 ? kobject_uevent_env+0x230/0x12c0
 bus_probe_device+0x1a2/0x260
 device_add+0xa61/0x1ce0
 ? __mutex_unlock_slowpath+0xe7/0x660
 ? __fw_devlink_link_to_suppliers+0x550/0x550
 usb_set_configuration+0x984/0x1770
 ? kernfs_create_link+0x175/0x230
 usb_generic_driver_probe+0x69/0x90
 usb_probe_device+0x9c/0x220
 really_probe+0x1be/0xa90
 __driver_probe_device+0x2ab/0x460
 driver_probe_device+0x49/0x120
 __device_attach_driver+0x18a/0x250
 ? driver_allows_async_probing+0x120/0x120
 bus_for_each_drv+0x123/0x1a0
 ? bus_rescan_devices+0x20/0x20
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 ? trace_hardirqs_on+0x1c/0x120
 __device_attach+0x207/0x330
 ? device_bind_driver+0xb0/0xb0
 ? kobject_uevent_env+0x230/0x12c0
 bus_probe_device+0x1a2/0x260
 device_add+0xa61/0x1ce0
 ? __fw_devlink_link_to_suppliers+0x550/0x550
 usb_new_device.cold+0x463/0xf66
 ? hub_disconnect+0x400/0x400
 ? _raw_spin_unlock_irq+0x24/0x30
 hub_event+0x10d5/0x3330
 ? hub_port_debounce+0x280/0x280
 ? __lock_acquire+0x1671/0x5790
 ? wq_calc_node_cpumask+0x170/0x2a0
 ? lock_release+0x640/0x640
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 process_one_work+0x873/0x13e0
 ? lock_release+0x640/0x640
 ? pwq_dec_nr_in_flight+0x320/0x320
 ? rwlock_bug.part.0+0x90/0x90
 worker_thread+0x8b/0xd10
 ? __kthread_parkme+0xd9/0x1d0
 ? pr
---truncated---

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2022-50551?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-50551?

Apply the vendor's patch.

## Is CVE-2022-50551 being exploited?

There is no known exploitation of CVE-2022-50551 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-2022-50551 and fix it if it is affected.

What it is: CVE-2022-50551 is a high-severity vulnerability in Linux kernel, published on 7 Oct 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-2022-50551 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-2022-50551/ (Markdown: https://insights.sbomify.com/CVE-2022-50551/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50551
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50551
- OSV: https://osv.dev/vulnerability/CVE-2022-50551

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50551/
Summaries are generated and may contain mistakes; the official description above is the record.