[PATCH] spi: spidev: fix possible NULL dereference

From: Sudip Mukherjee
Date: Thu Sep 10 2015 - 07:18:27 EST


During the last close we are freeing spidev if spidev->spi is NULL, but
just before checking if spidev->spi is NULL we are dereferencing it.
Lets add a check there to avoid the NULL dereference.

Signed-off-by: Sudip Mukherjee <sudip@xxxxxxxxxxxxxxx>
---
drivers/spi/spidev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index fba92a5..ef008e5 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -651,7 +651,8 @@ static int spidev_release(struct inode *inode, struct file *filp)
kfree(spidev->rx_buffer);
spidev->rx_buffer = NULL;

- spidev->speed_hz = spidev->spi->max_speed_hz;
+ if (spidev->spi)
+ spidev->speed_hz = spidev->spi->max_speed_hz;

/* ... after we unbound from the underlying device? */
spin_lock_irq(&spidev->spi_lock);
--
1.9.1

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