Re: [PATCH v1 1/2] ath10k: fix peer stats null pointer dereference

[Kalle Valo <kvalo@codeaurora.org>]

zhichen@codeaurora.org wrote:

> There was a race condition in SMP that an ath10k_peer was created but its
> member sta was null. Following are procedures of ath10k_peer creation and
> member sta access in peer statistics path.
> 
>     1. Peer creation:
>         ath10k_peer_create()
>             =>ath10k_wmi_peer_create()
>                 =>ath10k_wait_for_peer_created()
>                 ...
> 
>         # another kernel path, RX from firmware
>         ath10k_htt_t2h_msg_handler()
>         =>ath10k_peer_map_event()
>                 =>wake_up()
>                 # ar->peer_map[id] = peer //add peer to map
> 
>         #wake up original path from waiting
>                 ...
>                 # peer->sta = sta //sta assignment
> 
>     2.  RX path of statistics
>         ath10k_htt_t2h_msg_handler()
>             =>ath10k_update_per_peer_tx_stats()
>                 =>ath10k_htt_fetch_peer_stats()
>                 # peer->sta //sta accessing
> 
> Any access of peer->sta after peer was added to peer_map but before sta was
> assigned could cause a null pointer issue. And because these two steps are
> asynchronous, no proper lock can protect them. So both peer and sta need to
> be checked before access.
> 
> Tested: QCA9984 with firmware ver 10.4-3.9.0.1-00005
> Signed-off-by: Zhi Chen <zhichen@codeaurora.org>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

2 patches applied to ath-next branch of ath.git, thanks.

2d3b55853b12 ath10k: fix peer stats null pointer dereference
386f97e3b201 ath10k: fix tx_stats memory leak

-- 
https://patchwork.kernel.org/patch/10722983/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches