2023-10-19 15:33:08

by Johan Hovold

[permalink] [raw]
Subject: [PATCH v2 1/2] wifi: ath11k: fix temperature event locking

The ath11k active pdevs are protected by RCU but the temperature event
handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
read-side critical section as reported by RCU lockdep:

=============================
WARNING: suspicious RCU usage
6.6.0-rc6 #7 Not tainted
-----------------------------
drivers/net/wireless/ath/ath11k/mac.c:638 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
no locks held by swapper/0/0.
...
Call trace:
...
lockdep_rcu_suspicious+0x16c/0x22c
ath11k_mac_get_ar_by_pdev_id+0x194/0x1b0 [ath11k]
ath11k_wmi_tlv_op_rx+0xa84/0x2c1c [ath11k]
ath11k_htc_rx_completion_handler+0x388/0x510 [ath11k]

Mark the code in question as an RCU read-side critical section to avoid
any potential use-after-free issues.

Fixes: a41d10348b01 ("ath11k: add thermal sensor device support")
Cc: [email protected] # 5.7
Signed-off-by: Johan Hovold <[email protected]>
---
drivers/net/wireless/ath/ath11k/wmi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index 23ad6825e5be..da1582b8dc30 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -8383,14 +8383,17 @@ ath11k_wmi_pdev_temperature_event(struct ath11k_base *ab,
ath11k_dbg(ab, ATH11K_DBG_WMI, "event pdev temperature ev temp %d pdev_id %d\n",
ev->temp, ev->pdev_id);

+ rcu_read_lock();
+
ar = ath11k_mac_get_ar_by_pdev_id(ab, ev->pdev_id);
if (!ar) {
ath11k_warn(ab, "invalid pdev id in pdev temperature ev %d", ev->pdev_id);
- kfree(tb);
- return;
+ goto exit;
}

ath11k_thermal_event_temperature(ar, ev->temp);
+exit:
+ rcu_read_unlock();

kfree(tb);
}
--
2.41.0


2023-10-24 14:00:03

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] wifi: ath11k: fix temperature event locking

Johan Hovold <[email protected]> writes:

> The ath11k active pdevs are protected by RCU but the temperature event
> handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
> read-side critical section as reported by RCU lockdep:
>
> =============================
> WARNING: suspicious RCU usage
> 6.6.0-rc6 #7 Not tainted
> -----------------------------
> drivers/net/wireless/ath/ath11k/mac.c:638 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
> rcu_scheduler_active = 2, debug_locks = 1
> no locks held by swapper/0/0.
> ...
> Call trace:
> ...
> lockdep_rcu_suspicious+0x16c/0x22c
> ath11k_mac_get_ar_by_pdev_id+0x194/0x1b0 [ath11k]
> ath11k_wmi_tlv_op_rx+0xa84/0x2c1c [ath11k]
> ath11k_htc_rx_completion_handler+0x388/0x510 [ath11k]
>
> Mark the code in question as an RCU read-side critical section to avoid
> any potential use-after-free issues.
>
> Fixes: a41d10348b01 ("ath11k: add thermal sensor device support")
> Cc: [email protected] # 5.7
> Signed-off-by: Johan Hovold <[email protected]>

On what hardware and firmware version did you test this? As there's so
many different combos we use Tested-on tag to provide that information
in the commit message:

https://wireless.wiki.kernel.org/en/users/drivers/ath11k/submittingpatches#tested-on_tag

I can add that if you let me know what you used.

--
https://patchwork.kernel.org/project/linux-wireless/list/

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

2023-10-25 09:51:26

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] wifi: ath11k: fix temperature event locking

Johan Hovold <[email protected]> writes:

> On Tue, Oct 24, 2023 at 04:59:35PM +0300, Kalle Valo wrote:
>> Johan Hovold <[email protected]> writes:
>>
>> > The ath11k active pdevs are protected by RCU but the temperature event
>> > handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
>> > read-side critical section as reported by RCU lockdep:
>
>> On what hardware and firmware version did you test this? As there's so
>> many different combos we use Tested-on tag to provide that information
>> in the commit message:
>>
>> https://wireless.wiki.kernel.org/en/users/drivers/ath11k/submittingpatches#tested-on_tag
>>
>> I can add that if you let me know what you used.
>
> I hit this on the Lenovo Thinkpad X13s and I guess the tag should be:
>
> Tested-on: QCNFA765 hw2.1 WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23

From ath11k point of view QCNFA765 is WCN6855 so I used this one:

Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23

> Note that I've only been able to test the ath11k fixes (not the
> corresponding ath12k) and I only tested this particular patch fully

Thanks, I added Tested-on to this patch 1 and for the rest I added
"compile tested only".

--
https://patchwork.kernel.org/project/linux-wireless/list/

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

2023-10-25 09:59:47

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] wifi: ath11k: fix temperature event locking

Johan Hovold <[email protected]> wrote:

> The ath11k active pdevs are protected by RCU but the temperature event
> handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
> read-side critical section as reported by RCU lockdep:
>
> =============================
> WARNING: suspicious RCU usage
> 6.6.0-rc6 #7 Not tainted
> -----------------------------
> drivers/net/wireless/ath/ath11k/mac.c:638 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
> rcu_scheduler_active = 2, debug_locks = 1
> no locks held by swapper/0/0.
> ...
> Call trace:
> ...
> lockdep_rcu_suspicious+0x16c/0x22c
> ath11k_mac_get_ar_by_pdev_id+0x194/0x1b0 [ath11k]
> ath11k_wmi_tlv_op_rx+0xa84/0x2c1c [ath11k]
> ath11k_htc_rx_completion_handler+0x388/0x510 [ath11k]
>
> Mark the code in question as an RCU read-side critical section to avoid
> any potential use-after-free issues.
>
> Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
>
> Fixes: a41d10348b01 ("ath11k: add thermal sensor device support")
> Cc: [email protected] # 5.7
> Signed-off-by: Johan Hovold <[email protected]>
> Acked-by: Jeff Johnson <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

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

1a5352a81b47 wifi: ath11k: fix temperature event locking
3b6c14833165 wifi: ath11k: fix dfs radar event locking

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

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

2023-10-25 12:26:38

by Johan Hovold

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] wifi: ath11k: fix temperature event locking

On Wed, Oct 25, 2023 at 12:51:10PM +0300, Kalle Valo wrote:
> Johan Hovold <[email protected]> writes:

> > I hit this on the Lenovo Thinkpad X13s and I guess the tag should be:
> >
> > Tested-on: QCNFA765 hw2.1 WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
>
> From ath11k point of view QCNFA765 is WCN6855 so I used this one:
>
> Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
>
> > Note that I've only been able to test the ath11k fixes (not the
> > corresponding ath12k) and I only tested this particular patch fully
>
> Thanks, I added Tested-on to this patch 1 and for the rest I added
> "compile tested only".

Thanks for fixing that, I'll try to remember the Tested-on tag next
time.

Johan