spi: spidev: fix a potential use-after-free in spidev_release()
authorZhenzhong Duan <zhenzhong.duan@gmail.com>
Thu, 18 Jun 2020 03:21:25 +0000 (11:21 +0800)
committerMark Brown <broonie@kernel.org>
Thu, 18 Jun 2020 16:47:00 +0000 (17:47 +0100)
commit06096cc6c5a84ced929634b0d79376b94c65a4bd
tree20308a74b1a841161edebc9abcf1f566bfae01ca
parentabd42781c3d2155868821f1b947ae45bbc33330d
spi: spidev: fix a potential use-after-free in spidev_release()

If an spi device is unbounded from the driver before the release
process, there will be an NULL pointer reference when it's
referenced in spi_slave_abort().

Fix it by checking it's already freed before reference.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Link: https://lore.kernel.org/r/20200618032125.4650-2-zhenzhong.duan@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
drivers/spi/spidev.c