Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

wifi: brcmfmac: Check for probe() id argument being NULL

The probe() id argument may be NULL in 2 scenarios:

1. brcmf_pcie_pm_leave_D3() calling brcmf_pcie_probe() to reprobe the device.

2. If a user tries to manually bind the driver from sysfs then the sdio / pcie / usb probe() function gets called with NULL as id argument.

1. Is being hit by users causing the following oops on resume and causing wifi to stop working:

BUG: kernel NULL pointer dereference, address: 0000000000000018 <snip> Hardware name: Dell Inc. XPS 13 9350/0PWNCR, BIDS 1.13.0 02/10/2020 Workgueue: events_unbound async_run_entry_fn RIP: 0010:brcmf_pcie_probe+Ox16b/0x7a0 [brcmfmac] <snip> Call Trace: <TASK> brcmf_pcie_pm_leave_D3+0xc5/8x1a0 [brcmfmac be3b4cefca451e190fa35be8f00db1bbec293887] ? pci_pm_resume+0x5b/0xf0 ? pci_legacy_resume+0x80/0x80 dpm_run_callback+0x47/0x150 device_resume+0xa2/0x1f0 async_resume+0x1d/0x30 <snip>

Fix this by checking for id being NULL.

In the PCI and USB cases try a manual lookup of the id so that manually binding the driver through sysfs and more importantly brcmf_pcie_probe() on resume will work.

For the SDIO case there is no helper to do a manual sdio_device_id lookup, so just directly error out on a NULL id there.