[PATCH 4.9 166/177] vt6655: Fix a possible sleep-in-atomic bug in vt6655_suspend

From: Greg Kroah-Hartman
Date: Mon Dec 18 2017 - 12:04:41 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: Jia-Ju Bai <baijiaju1990@xxxxxxx>

[ Upstream commit 42c8eb3f6e15367981b274cb79ee4657e2c6949d ]

The driver may sleep under a spinlock, and the function call path is:
vt6655_suspend (acquire the spinlock)
__pci_start_power_transition (drivers/pci/pci.c)
msleep --> may sleep

To fix it, pci_set_power_state is called without having a spinlock.

This bug is found by my static analysis tool and my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/staging/vt6655/device_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/staging/vt6655/device_main.c
+++ b/drivers/staging/vt6655/device_main.c
@@ -1698,10 +1698,11 @@ static int vt6655_suspend(struct pci_dev

- pci_set_power_state(pcid, pci_choose_state(pcid, state));

spin_unlock_irqrestore(&priv->lock, flags);

+ pci_set_power_state(pcid, pci_choose_state(pcid, state));
return 0;