[PATCH 5.18 0312/1095] ath11k: fix netdev open race

Greg Kroah-Hartman
2022-08-15T20:53:18Z

From: Johan Hovold <johan+linaro@kernel.org>

[ Upstream commit d4ba1ff87b17e81686ada8f429300876f55f95ad ]

Make sure to allocate resources needed before registering the device.

This specifically avoids having a racing open() trigger a BUG_ON() in
mod_timer() when ath11k_mac_op_start() is called before the
mon_reap_timer as been set up.

I did not see this issue with next-20220310, but I hit it on every probe
with next-20220511. Perhaps some timing changed in between.

Here's the backtrace:

[ 51.346947] kernel BUG at kernel/time/timer.c:990!
[ 51.346958] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
...
[ 51.578225] Call trace:
[ 51.583293] __mod_timer+0x298/0x390
[ 51.589518] mod_timer+0x14/0x20
[ 51.595368] ath11k_mac_op_start+0x41c/0x4a0 [ath11k]
[ 51.603165] drv_start+0x38/0x60 [mac80211]
[ 51.610110] ieee80211_do_open+0x29c/0x7d0 [mac80211]
[ 51.617945] ieee80211_open+0x60/0xb0 [mac80211]
[ 51.625311] __dev_open+0x100/0x1c0
[ 51.631420] __dev_change_flags+0x194/0x210
[ 51.638214] dev_change_flags+0x24/0x70
[ 51.644646] do_setlink+0x228/0xdb0
[ 51.650723] __rtnl_newlink+0x460/0x830
[ 51.657162] rtnl_newlink+0x4c/0x80
[ 51.663229] rtnetlink_rcv_msg+0x124/0x390
[ 51.669917] netlink_rcv_skb+0x58/0x130
[ 51.676314] rtnetlink_rcv+0x18/0x30
[ 51.682460] netlink_unicast+0x250/0x310
[ 51.688960] netlink_sendmsg+0x19c/0x3e0
[ 51.695458] ____sys_sendmsg+0x220/0x290
[ 51.701938] ___sys_sendmsg+0x7c/0xc0
[ 51.708148] __sys_sendmsg+0x68/0xd0
[ 51.714254] __arm64_sys_sendmsg+0x28/0x40
[ 51.720900] invoke_syscall+0x48/0x120

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Fixes: 840c36fa727a ("ath11k: dp: stop rx pktlog before suspend")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220517103436.15867-1-johan+linaro@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/ath11k/core.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c
index 90a5df1fbdbd..0106e529f3c5 100644
--- a/drivers/net/wireless/ath/ath11k/core.c
+++ b/drivers/net/wireless/ath/ath11k/core.c
@@ -903,23 +903,23 @@ static int ath11k_core_pdev_create(struct ath11k_base *ab)
return ret;
}

- ret = ath11k_mac_register(ab);
+ ret = ath11k_dp_pdev_alloc(ab);
if (ret) {
- ath11k_err(ab, "failed register the radio with mac80211: %d\n", ret);
+ ath11k_err(ab, "failed to attach DP pdev: %d\n", ret);
goto err_pdev_debug;
}

- ret = ath11k_dp_pdev_alloc(ab);
+ ret = ath11k_mac_register(ab);
if (ret) {
- ath11k_err(ab, "failed to attach DP pdev: %d\n", ret);
- goto err_mac_unregister;
+ ath11k_err(ab, "failed register the radio with mac80211: %d\n", ret);
+ goto err_dp_pdev_free;
}

ret = ath11k_thermal_register(ab);
if (ret) {
ath11k_err(ab, "could not register thermal device: %d\n",
ret);
- goto err_dp_pdev_free;
+ goto err_mac_unregister;
}

ret = ath11k_spectral_init(ab);
@@ -932,10 +932,10 @@ static int ath11k_core_pdev_create(struct ath11k_base *ab)

err_thermal_unregister:
ath11k_thermal_unregister(ab);
-err_dp_pdev_free:
- ath11k_dp_pdev_free(ab);
err_mac_unregister:
ath11k_mac_unregister(ab);
+err_dp_pdev_free:
+ ath11k_dp_pdev_free(ab);
err_pdev_debug:
ath11k_debugfs_pdev_destroy(ab);

--
2.35.1