Patch "wifi: ath11k: fix a possible dead lock caused by ab->base_lock" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: ath11k: fix a possible dead lock caused by ab->base_lock

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-ath11k-fix-a-possible-dead-lock-caused-by-ab-ba.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b3632f753a9ab6498769a38a58ce0d6756529a84
Author: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
Date:   Thu Jan 11 15:56:57 2024 +0200

    wifi: ath11k: fix a possible dead lock caused by ab->base_lock
    
    [ Upstream commit cf2df0080bd59cb97a1519ddefaf59788febdaa5 ]
    
    spin_lock()/spin_unlock() are used in ath11k_reg_chan_list_event() to
    acquire/release ab->base_lock. For now this is safe because that
    function is only called in soft IRQ context.
    
    But ath11k_reg_chan_list_event() will be called from process
    context in an upcoming patch, and this can result in a deadlock if
    ab->base_lock is acquired in process context and then soft IRQ occurs
    on the same CPU and tries to acquire that lock.
    
    Fix it by using spin_lock_bh() and spin_unlock_bh() instead.
    
    Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
    
    Fixes: 69a0fcf8a9f2 ("ath11k: Avoid reg rules update during firmware recovery")
    Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
    Signed-off-by: Wen Gong <quic_wgong@xxxxxxxxxxx>
    Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
    Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
    Link: https://msgid.link/20231218085844.2658-4-quic_bqiang@xxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/ath/ath11k/reg.c b/drivers/net/wireless/ath/ath11k/reg.c
index adcd9063a59c3..d4fd3509e608c 100644
--- a/drivers/net/wireless/ath/ath11k/reg.c
+++ b/drivers/net/wireless/ath/ath11k/reg.c
@@ -852,13 +852,13 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
 	/* Avoid default reg rule updates sent during FW recovery if
 	 * it is already available
 	 */
-	spin_lock(&ab->base_lock);
+	spin_lock_bh(&ab->base_lock);
 	if (test_bit(ATH11K_FLAG_RECOVERY, &ab->dev_flags) &&
 	    ab->default_regd[pdev_idx]) {
-		spin_unlock(&ab->base_lock);
+		spin_unlock_bh(&ab->base_lock);
 		goto retfail;
 	}
-	spin_unlock(&ab->base_lock);
+	spin_unlock_bh(&ab->base_lock);
 
 	if (pdev_idx >= ab->num_radios) {
 		/* Process the event for phy0 only if single_pdev_only
@@ -911,7 +911,7 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
 		ab->reg_info_store[pdev_idx] = *reg_info;
 	}
 
-	spin_lock(&ab->base_lock);
+	spin_lock_bh(&ab->base_lock);
 	if (ab->default_regd[pdev_idx]) {
 		/* The initial rules from FW after WMI Init is to build
 		 * the default regd. From then on, any rules updated for
@@ -931,7 +931,7 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
 		ab->default_regd[pdev_idx] = regd;
 	}
 	ab->dfs_region = reg_info->dfs_region;
-	spin_unlock(&ab->base_lock);
+	spin_unlock_bh(&ab->base_lock);
 
 	return 0;