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

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

[Johan Hovold]

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: stable@vger.kernel.org      # 5.7
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 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

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

[Jeff Johnson]

On 10/19/2023 8:31 AM, Johan Hovold 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.
> 
> Fixes: a41d10348b01 ("ath11k: add thermal sensor device support")
> Cc: stable@vger.kernel.org      # 5.7
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>

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

[Kalle Valo]

Johan Hovold <johan+linaro@kernel.org> 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: stable@vger.kernel.org      # 5.7
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

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

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

[Johan Hovold]

On Tue, Oct 24, 2023 at 04:59:35PM +0300, Kalle Valo wrote:
> Johan Hovold <johan+linaro@kernel.org> 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

Note that I've only been able to test the ath11k fixes (not the
corresponding ath12k) and I only tested this particular patch fully
(e.g. since I didn't trigger any radar events).

Johan

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

[Kalle Valo]

Johan Hovold <johan@kernel.org> writes:

> On Tue, Oct 24, 2023 at 04:59:35PM +0300, Kalle Valo wrote:
>> Johan Hovold <johan+linaro@kernel.org> 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

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

[Johan Hovold]

On Wed, Oct 25, 2023 at 12:51:10PM +0300, Kalle Valo wrote:
> Johan Hovold <johan@kernel.org> 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

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

[Kalle Valo]

Johan Hovold <johan+linaro@kernel.org> 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: stable@vger.kernel.org      # 5.7
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

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/20231019153115.26401-2-johan+linaro@kernel.org/

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

[PATCH v2 2/2] wifi: ath11k: fix dfs radar event locking

[Johan Hovold]

The ath11k active pdevs are protected by RCU but the DFS radar event
handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
read-side critical section.

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

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Cc: stable@vger.kernel.org      # 5.6
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/net/wireless/ath/ath11k/wmi.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index da1582b8dc30..f0eac6cb84fd 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -8337,6 +8337,8 @@ ath11k_wmi_pdev_dfs_radar_detected_event(struct ath11k_base *ab, struct sk_buff
 		   ev->detector_id, ev->segment_id, ev->timestamp, ev->is_chirp,
 		   ev->freq_offset, ev->sidx);
 
+	rcu_read_lock();
+
 	ar = ath11k_mac_get_ar_by_pdev_id(ab, ev->pdev_id);
 
 	if (!ar) {
@@ -8354,6 +8356,8 @@ ath11k_wmi_pdev_dfs_radar_detected_event(struct ath11k_base *ab, struct sk_buff
 		ieee80211_radar_detected(ar->hw);
 
 exit:
+	rcu_read_unlock();
+
 	kfree(tb);
 }
 
-- 
2.41.0