Re: [PATCH] rtw89: fix RCU usage in rtw89_core_txq_push()

[Kalle Valo]

Jiri Kosina <jkosina@xxxxxxx> wrote:

> From: Jiri Kosina <jkosina@xxxxxxx>
> Subject: [PATCH] rtw89: fix RCU usage in rtw89_core_txq_push()
> 
> ieee80211_tx_h_select_key() is performing a series of RCU dereferences,
> but rtw89_core_txq_push() is calling it (via ieee80211_tx_dequeue_ni())
> without RCU read-side lock held; fix that.
> 
> This addresses the splat below.
> 
>  =============================
>  WARNING: suspicious RCU usage
>  5.17.0-rc4-00003-gccad664b7f14 #3 Tainted: G            E
>  -----------------------------
>  net/mac80211/tx.c:593 suspicious rcu_dereference_check() usage!
> 
>  other info that might help us debug this:
> 
>  rcu_scheduler_active = 2, debug_locks = 1
>  2 locks held by kworker/u33:0/184:
>   #0: ffff9c0b14811d38 ((wq_completion)rtw89_tx_wq){+.+.}-{0:0}, at: process_one_work+0x258/0x660
>   #1: ffffb97380cf3e78 ((work_completion)(&rtwdev->txq_work)){+.+.}-{0:0}, at: process_one_work+0x258/0x660
> 
>  stack backtrace:
>  CPU: 8 PID: 184 Comm: kworker/u33:0 Tainted: G            E     5.17.0-rc4-00003-gccad664b7f14 #3 473b49ab0e7c2d6af2900c756bfd04efd7a9de13
>  Hardware name: LENOVO 20UJS2B905/20UJS2B905, BIOS R1CET63W(1.32 ) 04/09/2021
>  Workqueue: rtw89_tx_wq rtw89_core_txq_work [rtw89_core]
>  Call Trace:
>   <TASK>
>   dump_stack_lvl+0x58/0x71
>   ieee80211_tx_h_select_key+0x2c0/0x530 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365]
>   ieee80211_tx_dequeue+0x1a7/0x1260 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365]
>   rtw89_core_txq_work+0x1a6/0x420 [rtw89_core b39ba493f2e517ad75e0f8187ecc24edf58bbbea]
>   process_one_work+0x2d8/0x660
>   worker_thread+0x39/0x3e0
>   ? process_one_work+0x660/0x660
>   kthread+0xe5/0x110
>   ? kthread_complete_and_exit+0x20/0x20
>   ret_from_fork+0x22/0x30
>   </TASK>
> 
>  =============================
>  WARNING: suspicious RCU usage
>  5.17.0-rc4-00003-gccad664b7f14 #3 Tainted: G            E
>  -----------------------------
>  net/mac80211/tx.c:607 suspicious rcu_dereference_check() usage!
> 
>  other info that might help us debug this:
> 
>  rcu_scheduler_active = 2, debug_locks = 1
>  2 locks held by kworker/u33:0/184:
>   #0: ffff9c0b14811d38 ((wq_completion)rtw89_tx_wq){+.+.}-{0:0}, at: process_one_work+0x258/0x660
>   #1: ffffb97380cf3e78 ((work_completion)(&rtwdev->txq_work)){+.+.}-{0:0}, at: process_one_work+0x258/0x660
> 
>  stack backtrace:
>  CPU: 8 PID: 184 Comm: kworker/u33:0 Tainted: G            E     5.17.0-rc4-00003-gccad664b7f14 #3 473b49ab0e7c2d6af2900c756bfd04efd7a9de13
>  Hardware name: LENOVO 20UJS2B905/20UJS2B905, BIOS R1CET63W(1.32 ) 04/09/2021
>  Workqueue: rtw89_tx_wq rtw89_core_txq_work [rtw89_core]
>  Call Trace:
>   <TASK>
>   dump_stack_lvl+0x58/0x71
>   ieee80211_tx_h_select_key+0x464/0x530 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365]
>   ieee80211_tx_dequeue+0x1a7/0x1260 [mac80211 911c23e2351c0ae60b597a67b1204a5ea955e365]
>   rtw89_core_txq_work+0x1a6/0x420 [rtw89_core b39ba493f2e517ad75e0f8187ecc24edf58bbbea]
>   process_one_work+0x2d8/0x660
>   worker_thread+0x39/0x3e0
>   ? process_one_work+0x660/0x660
>   kthread+0xe5/0x110
>   ? kthread_complete_and_exit+0x20/0x20
>   ret_from_fork+0x22/0x30
>   </TASK>
> 
> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
> Acked-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>

Patch applied to wireless-next.git, thanks.

f3d825a35920 rtw89: fix RCU usage in rtw89_core_txq_push()

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/nycvar.YFH.7.76.2202152037000.11721@xxxxxxxxxxxxx/

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