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Subject[PATCH] cw1200: Fix a sleep-in-atomic bug in cw1200_tx_confirm_cb and cw1200_cqm_bssloss_sm
Date
The driver may sleep under a spin lock, and the function call path is:
cw1200_tx_confirm_cb (acquire the lock by spin_lock)
__cw1200_cqm_bssloss_sm
cancel_work_sync --> may sleep

cw1200_cqm_bssloss_sm
__cw1200_cqm_bssloss_sm
cancel_work_sync --> may sleep

To fix it, the lock is released before cancel_work_sync, and the lock
is acquired again after this function.

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
drivers/net/wireless/st/cw1200/sta.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/st/cw1200/sta.c b/drivers/net/wireless/st/cw1200/sta.c
index a522248..d5f7698 100644
--- a/drivers/net/wireless/st/cw1200/sta.c
+++ b/drivers/net/wireless/st/cw1200/sta.c
@@ -154,7 +154,9 @@ void __cw1200_cqm_bssloss_sm(struct cw1200_common *priv,
int tx = 0;

priv->delayed_link_loss = 0;
+ spin_unlock(&priv->bss_loss_lock);
cancel_work_sync(&priv->bss_params_work);
+ spin_lock(&priv->bss_loss_lock);

pr_debug("[STA] CQM BSSLOSS_SM: state: %d init %d good %d bad: %d txlock: %d uj: %d\n",
priv->bss_loss_state,
--
1.7.9.5

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