[PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Niels Dossche]

ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
held when calling that function in order to protect the list. All
callers except ath11k_mac_op_unassign_vif_chanctx have that lock
acquired when calling ath11k_peer_find_by_addr. That lock is also not
transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
The solution is to acquire the lock when calling
ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.

Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
---
 drivers/net/wireless/ath/ath11k/mac.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 07f499d5ec92..5db2333478a2 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -7077,9 +7077,15 @@ ath11k_mac_op_unassign_vif_chanctx(struct ieee80211_hw *hw,
 	WARN_ON(!arvif->is_started);
 
 	if (ab->hw_params.vdev_start_delay &&
-	    arvif->vdev_type == WMI_VDEV_TYPE_MONITOR &&
-	    ath11k_peer_find_by_addr(ab, ar->mac_addr))
-		ath11k_peer_delete(ar, arvif->vdev_id, ar->mac_addr);
+	    arvif->vdev_type == WMI_VDEV_TYPE_MONITOR) {
+		struct ath11k_peer *peer;
+
+		spin_lock_bh(&ab->base_lock);
+		peer = ath11k_peer_find_by_addr(ab, ar->mac_addr);
+		spin_unlock_bh(&ab->base_lock);
+		if (peer)
+			ath11k_peer_delete(ar, arvif->vdev_id, ar->mac_addr);
+	}
 
 	if (arvif->vdev_type == WMI_VDEV_TYPE_MONITOR) {
 		ret = ath11k_mac_monitor_stop(ar);
-- 
2.35.1

Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Kalle Valo]

Niels Dossche <dossche.niels@gmail.com> writes:

> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
> held when calling that function in order to protect the list. All
> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
> acquired when calling ath11k_peer_find_by_addr. That lock is also not
> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
> The solution is to acquire the lock when calling
> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
>
> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>

On what hardware and firmware version did you test this?

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Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Niels Dossche]

On 3/16/22 07:13, Kalle Valo wrote:
> Niels Dossche <dossche.niels@gmail.com> writes:
> 
>> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
>> held when calling that function in order to protect the list. All
>> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
>> acquired when calling ath11k_peer_find_by_addr. That lock is also not
>> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
>> The solution is to acquire the lock when calling
>> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
>>
>> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
>> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
> 
> On what hardware and firmware version did you test this?
> 

Hi Kalle

Thanks for your reply.
I am currently working on a static analyser to detect missing locks.
This was a reported case. I manually verified the report by looking
at the code, so that I do not send wrong information or patches.
After concluding that this seems to be a true positive, I created this patch.
However, as I do not in fact have this particular hardware, I was unable to test it.

Thanks

Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Kalle Valo]

Niels Dossche <dossche.niels@gmail.com> writes:

> On 3/16/22 07:13, Kalle Valo wrote:
>> Niels Dossche <dossche.niels@gmail.com> writes:
>> 
>>> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
>>> held when calling that function in order to protect the list. All
>>> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
>>> acquired when calling ath11k_peer_find_by_addr. That lock is also not
>>> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
>>> The solution is to acquire the lock when calling
>>> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
>>>
>>> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
>>> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
>> 
>> On what hardware and firmware version did you test this?
>> 
>
> Thanks for your reply.
> I am currently working on a static analyser to detect missing locks.
> This was a reported case. I manually verified the report by looking
> at the code, so that I do not send wrong information or patches.
> After concluding that this seems to be a true positive, I created this patch.
> However, as I do not in fact have this particular hardware, I was unable to test it.

Ah, I didn't realise this. If you are using a tool to find errors in the
code it's always a good idea to document that in the commit log. I'll
add an edited version of what wrote you above in the commit log, ok?

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Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Niels Dossche]

On 16/03/2022 15:34, Kalle Valo wrote:
> Niels Dossche <dossche.niels@gmail.com> writes:
> 
>> On 3/16/22 07:13, Kalle Valo wrote:
>>> Niels Dossche <dossche.niels@gmail.com> writes:
>>>
>>>> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
>>>> held when calling that function in order to protect the list. All
>>>> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
>>>> acquired when calling ath11k_peer_find_by_addr. That lock is also not
>>>> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
>>>> The solution is to acquire the lock when calling
>>>> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
>>>>
>>>> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
>>>> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
>>>
>>> On what hardware and firmware version did you test this?
>>>
>>
>> Thanks for your reply.
>> I am currently working on a static analyser to detect missing locks.
>> This was a reported case. I manually verified the report by looking
>> at the code, so that I do not send wrong information or patches.
>> After concluding that this seems to be a true positive, I created this patch.
>> However, as I do not in fact have this particular hardware, I was unable to test it.
> 
> Ah, I didn't realise this. If you are using a tool to find errors in the
> code it's always a good idea to document that in the commit log. I'll
> add an edited version of what wrote you above in the commit log, ok?
> 

I will make sure to write that in future commits, sorry for the inconvenience.
Adding an edited version of what I write to the commit log is okay for me, thanks!

Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Kalle Valo]

Niels Dossche <dossche.niels@gmail.com> writes:

> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
> held when calling that function in order to protect the list. All
> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
> acquired when calling ath11k_peer_find_by_addr. That lock is also not
> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
> The solution is to acquire the lock when calling
> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
>
> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
> ---
>  drivers/net/wireless/ath/ath11k/mac.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
> index 07f499d5ec92..5db2333478a2 100644
> --- a/drivers/net/wireless/ath/ath11k/mac.c
> +++ b/drivers/net/wireless/ath/ath11k/mac.c
> @@ -7077,9 +7077,15 @@ ath11k_mac_op_unassign_vif_chanctx(struct ieee80211_hw *hw,
>  	WARN_ON(!arvif->is_started);
>  
>  	if (ab->hw_params.vdev_start_delay &&
> -	    arvif->vdev_type == WMI_VDEV_TYPE_MONITOR &&
> -	    ath11k_peer_find_by_addr(ab, ar->mac_addr))
> -		ath11k_peer_delete(ar, arvif->vdev_id, ar->mac_addr);
> +	    arvif->vdev_type == WMI_VDEV_TYPE_MONITOR) {
> +		struct ath11k_peer *peer;

In the pending branch I moved the declaration to the beginning of the
function and added this to the commit log:

"I am currently working on a static analyser to detect missing locks and
this was a reported case. I manually verified the report by looking at
the code, but I do not have real hardware so this is compile tested
only."

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Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Niels Dossche]

On 21/03/2022 11:45, Kalle Valo wrote:
> Niels Dossche <dossche.niels@gmail.com> writes:
> 
>> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
>> held when calling that function in order to protect the list. All
>> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
>> acquired when calling ath11k_peer_find_by_addr. That lock is also not
>> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
>> The solution is to acquire the lock when calling
>> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
>>
>> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
>> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
>> ---
>>  drivers/net/wireless/ath/ath11k/mac.c | 12 +++++++++---
>>  1 file changed, 9 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
>> index 07f499d5ec92..5db2333478a2 100644
>> --- a/drivers/net/wireless/ath/ath11k/mac.c
>> +++ b/drivers/net/wireless/ath/ath11k/mac.c
>> @@ -7077,9 +7077,15 @@ ath11k_mac_op_unassign_vif_chanctx(struct ieee80211_hw *hw,
>>  	WARN_ON(!arvif->is_started);
>>  
>>  	if (ab->hw_params.vdev_start_delay &&
>> -	    arvif->vdev_type == WMI_VDEV_TYPE_MONITOR &&
>> -	    ath11k_peer_find_by_addr(ab, ar->mac_addr))
>> -		ath11k_peer_delete(ar, arvif->vdev_id, ar->mac_addr);
>> +	    arvif->vdev_type == WMI_VDEV_TYPE_MONITOR) {
>> +		struct ath11k_peer *peer;
> 
> In the pending branch I moved the declaration to the beginning of the
> function and added this to the commit log:
> 
> "I am currently working on a static analyser to detect missing locks and
> this was a reported case. I manually verified the report by looking at
> the code, but I do not have real hardware so this is compile tested
> only."
> 

Sounds good to me. Thanks!

Re: [PATCH] ath11k: acquire ab->base_lock in unassign when finding the peer by addr

[Kalle Valo]

Niels Dossche <dossche.niels@gmail.com> wrote:

> ath11k_peer_find_by_addr states via lockdep that ab->base_lock must be
> held when calling that function in order to protect the list. All
> callers except ath11k_mac_op_unassign_vif_chanctx have that lock
> acquired when calling ath11k_peer_find_by_addr. That lock is also not
> transitively held by a path towards ath11k_mac_op_unassign_vif_chanctx.
> The solution is to acquire the lock when calling
> ath11k_peer_find_by_addr inside ath11k_mac_op_unassign_vif_chanctx.
> 
> I am currently working on a static analyser to detect missing locks and
> this was a reported case. I manually verified the report by looking at
> the code, but I do not have real hardware so this is compile tested
> only.
> 
> Fixes: 701e48a43e15 ("ath11k: add packet log support for QCA6390")
> Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Patch applied to ath-next branch of ath.git, thanks.

2db80f93869d ath11k: acquire ab->base_lock in unassign when finding the peer by addr

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