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| author | Johan Hovold <johan@kernel.org> | 2017-10-30 11:35:25 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-21 09:49:24 +0100 |
| commit | 9aacd82304adb74fa9320cb1c5d4bc71b1b91f06 (patch) | |
| tree | 3d1de9fbcef4ef03d4a3fb63e9a624e04053c1ba | |
| parent | d3e36fd07b5b27768db8353a83dec0459bf2ee33 (diff) | |
| download | linux-stable-9aacd82304adb74fa9320cb1c5d4bc71b1b91f06.tar.gz linux-stable-9aacd82304adb74fa9320cb1c5d4bc71b1b91f06.tar.bz2 linux-stable-9aacd82304adb74fa9320cb1c5d4bc71b1b91f06.zip | |
spi: fix use-after-free at controller deregistration
commit 67f7b2781fafcc0f52464880154b320fea1ae982 upstream.
The controller is typically freed as part of device_unregister() so
store the bus id before deregistration to avoid use-after-free when the
id is later released.
Fixes: 9b61e302210e ("spi: Pick spi bus number from Linux idr or spi alias")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/spi/spi.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index e8b5a5e21b2e..3ff0ee88c467 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2245,11 +2245,12 @@ static int __unregister(struct device *dev, void *null) void spi_unregister_controller(struct spi_controller *ctlr) { struct spi_controller *found; + int id = ctlr->bus_num; int dummy; /* First make sure that this controller was ever added */ mutex_lock(&board_lock); - found = idr_find(&spi_master_idr, ctlr->bus_num); + found = idr_find(&spi_master_idr, id); mutex_unlock(&board_lock); if (found != ctlr) { dev_dbg(&ctlr->dev, @@ -2269,7 +2270,7 @@ void spi_unregister_controller(struct spi_controller *ctlr) device_unregister(&ctlr->dev); /* free bus id */ mutex_lock(&board_lock); - idr_remove(&spi_master_idr, ctlr->bus_num); + idr_remove(&spi_master_idr, id); mutex_unlock(&board_lock); } EXPORT_SYMBOL_GPL(spi_unregister_controller); |