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.
- 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
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
Which versions are affected by CVE-2022-50551?
It affects 1 product.
Products include 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
Sources
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.