spi: spidev: fix possible NULL dereference

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.

Fixes: 9169051617 ("spi: spidev: Don't mangle max_speed_hz in underlying spi device")
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Sudip Mukherjee 2015-09-10 16:48:13 +05:30 committed by Mark Brown
parent bc0195aad0
commit dd85ebf681

View File

@ -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);