Re: [PATCH net] wifi: mac80211: fix memory leak in ieee80211_register_hw()

[Jeff Johnson <jeff.johnson@oss.qualcomm.com>]

On 6/8/2026 7:55 AM, Dawei Feng wrote:
> If kmemdup() fails while copying supported band structures, the error
> path jumps to fail_rate. This skips rate_control_deinitialize() and
> leaks the initialized local->rate_ctrl.
> 
> Fix this by redirecting the error path to fail_wiphy_register to
> ensure proper cleanup.
> 
> The bug was first flagged by an experimental analysis tool we are
> developing for kernel memory-management bugs while analyzing
> v6.13-rc1. The tool is still under development and is not yet publicly
> available. Manual inspection confirms that the bug is still present in
> v7.1-rc7.
> 
> An x86_64 allyesconfig build showed no new warnings. As we do not have a
> suitable mac80211 device/driver combination to test with, no runtime
> testing was able to be performed.
> 
> Fixes: 09b4a4faf9d0 ("mac80211: introduce capability flags for VHT EXT NSS support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Zilin Guan <zilin@seu.edu.cn>

why is this SOB here?

> Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>

this is the posted author of the patch, and this patch hasn't been posted
previously, so it is unclear why there is an additional S-o-b

> ---
>  net/mac80211/main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
> index f47dd58770ad..9306e0af3b5f 100644
> --- a/net/mac80211/main.c
> +++ b/net/mac80211/main.c
> @@ -1599,7 +1599,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
>  		sband = kmemdup(sband, sizeof(*sband), GFP_KERNEL);
>  		if (!sband) {
>  			result = -ENOMEM;
> -			goto fail_rate;
> +			goto fail_wiphy_register;

I'm wondering if it would be more logical to have another label at the same
place, i.e. fail_band, since it is illogical to goto fail_wiphy_register when
you aren't performing the wiphy_register function

>  		}
>  
>  		wiphy_dbg(hw->wiphy, "copying sband (band %d) due to VHT EXT NSS BW flag\n",