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authorMarek Szyprowski <m.szyprowski@samsung.com>2020-11-24 14:15:23 +0100
committerMark Brown <broonie@kernel.org>2020-11-24 15:14:39 +0100
commita6f483b2e4415bca7af90346204f93f63b90acdd (patch)
treec43fed048c1eeea4a5dbdfb4f78015bbb577c206 /drivers/spi/spi.c
parentspi: amd: Use devm_platform_ioremap_resource() in amd_spi_probe (diff)
downloadlinux-a6f483b2e4415bca7af90346204f93f63b90acdd.tar.xz
linux-a6f483b2e4415bca7af90346204f93f63b90acdd.zip
spi: Fix potential NULL pointer dereference in spi_shutdown()
Shutdown bus function might be called on the unbound device, so add a check if there is a driver before calling its shutdown function. This fixes following kernel panic obserbed during system reboot: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018 ... Call trace: spi_shutdown+0x10/0x38 kernel_restart_prepare+0x34/0x40 kernel_restart+0x14/0x88 __do_sys_reboot+0x148/0x248 __arm64_sys_reboot+0x1c/0x28 el0_svc_common.constprop.3+0x74/0x198 do_el0_svc+0x20/0x98 el0_sync_handler+0x140/0x1a8 el0_sync+0x140/0x180 Code: f9403402 d1008041 f100005f 9a9f1021 (f9400c21) ---[ end trace 266c07205a2d632e ]--- Fixes: 9db34ee64ce4 (spi: Use bus_type functions for probe, remove and shutdown) Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20201124131523.32287-1-m.szyprowski@samsung.com Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r--drivers/spi/spi.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6ee0f66ddef1..1564914930d8 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -426,10 +426,12 @@ static int spi_remove(struct device *dev)
static void spi_shutdown(struct device *dev)
{
- const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+ if (dev->driver) {
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
- if (sdrv->shutdown)
- sdrv->shutdown(to_spi_device(dev));
+ if (sdrv->shutdown)
+ sdrv->shutdown(to_spi_device(dev));
+ }
}
struct bus_type spi_bus_type = {