Re: [PATCH v2] wifi: brcmfmac: Check for probe() id argument being NULL

[Arend van Spriel <arend.vanspriel@broadcom.com>]

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On 5/10/2023 4:18 PM, Hans de Goede wrote:
> 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.
> 
> Fixes: da6d9c8ecd00 ("wifi: brcmfmac: add firmware vendor info in driver info")
> Reported-by: Felix <nimrod4garoa@gmail.com>
> Link: https://lore.kernel.org/regressions/4ef3f252ff530cbfa336f5a0d80710020fc5cb1e.camel@gmail.com/
> Cc: Arend van Spriel <arend.vanspriel@broadcom.com>

You can change this to:

Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> - Using BRCMF_FWVENDOR_INVALID will just lead to a probe() error later on,
>    if NULL error out immediately instead of using BRCMF_FWVENDOR_INVALID.
> ---
>   .../net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c |  5 +++++
>   .../net/wireless/broadcom/brcm80211/brcmfmac/pcie.c   | 11 +++++++++++
>   .../net/wireless/broadcom/brcm80211/brcmfmac/usb.c    | 11 +++++++++++
>   3 files changed, 27 insertions(+)

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