[PATCH 4.19 035/321] can: mcp251x: mcp251x_restart_work_handler(): Fix potential force_quit race condition

Greg Kroah-Hartman
2019-12-03T22:46:44Z

From: Timo Schlüßler <schluessler@krause.de>

[ Upstream commit 27a0e54bae09d2dd023a01254db506d61cc50ba1 ]

In mcp251x_restart_work_handler() the variable to stop the interrupt
handler (priv->force_quit) is reset after the chip is restarted and thus
a interrupt might occur.

This patch fixes the potential race condition by resetting force_quit
before enabling interrupts.

Signed-off-by: Timo Schlüßler <schluessler@krause.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/can/spi/mcp251x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index de8d9dceb1236..0b0dd3f096dc6 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -773,6 +773,7 @@ static void mcp251x_restart_work_handler(struct work_struct *ws)
if (priv->after_suspend) {
mcp251x_hw_reset(spi);
mcp251x_setup(net, spi);
+ priv->force_quit = 0;
if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
mcp251x_set_normal_mode(spi);
} else if (priv->after_suspend & AFTER_SUSPEND_UP) {
@@ -784,7 +785,6 @@ static void mcp251x_restart_work_handler(struct work_struct *ws)
mcp251x_hw_sleep(spi);
}
priv->after_suspend = 0;
- priv->force_quit = 0;
}

if (priv->restart_tx) {
--
2.20.1