2023-04-21 22:19:00

by Larry Finger

[permalink] [raw]
Subject: Re: [PATCH v2] b43legacy: Add checking for null for ssb_get_devtypedata(dev)

On 4/18/23 09:29, Nikita Zhandarovich wrote:
> Since second call of ssb_get_devtypedata() may fail as well as the
> first one, the NULL return value in 'wl' will be later dereferenced in
> calls to b43legacy_one_core_attach() and schedule_work().
>
> Instead of merely warning about this failure with
> B43legacy_WARN_ON(), properly return with error to avoid any further
> NULL pointer dereferences.
>
> Found by Linux Verification Center (linuxtesting.org) with static
> analysis tool SVACE.
>
> Fixes: 75388acd0cd8 ("[B43LEGACY]: add mac80211-based driver for legacy BCM43xx devices")
> Co-developed-by: Natalia Petrova <[email protected]>
> Signed-off-by: Nikita Zhandarovich <[email protected]>
> ---
> v2: fix issues with overlooked null-ptr-dereferences pointed out by
> Simon Horman <[email protected]>
> Link: https://lore.kernel.org/all/[email protected]/
>
> drivers/net/wireless/broadcom/b43legacy/main.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c
> index 760136638a95..5a706dd0b1a4 100644
> --- a/drivers/net/wireless/broadcom/b43legacy/main.c
> +++ b/drivers/net/wireless/broadcom/b43legacy/main.c
> @@ -3857,7 +3857,11 @@ static int b43legacy_probe(struct ssb_device *dev,
> if (err)
> goto out;
> wl = ssb_get_devtypedata(dev);
> - B43legacy_WARN_ON(!wl);
> + if (!wl) {
> + B43legacy_WARN_ON(!wl);
> + err = -ENODEV;
> + goto out;
> + }
> }
> err = b43legacy_one_core_attach(dev, wl);
> if (err)

I do not recall seeing v1. One additional nitpick: The latest convention would
have the subject as "wifi: b43legacy:...". Kalle may be able to fix this on
merging, but it not, a v3 might be required. Otherwise, the patch is good.

Reviewed-by: Larry Finger <[email protected]>

Thanks,

Larry