published October 7, 2025
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
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