From fc68f42aa737dc15e7665a4101d4168aadb8e4c4 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 24 Jul 2021 15:25:54 -0700 Subject: [PATCH] ACPI: fix NULL pointer dereference Commit 71f642833284 ("ACPI: utils: Fix reference counting in for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer that was possibly NULL. That fails miserably, because that helper inline function is not set up to handle that case. Just make acpi_dev_put() silently accept a NULL pointer, rather than calling down to put_device() with an invalid offset off that NULL pointer. Link: https://lore.kernel.org/lkml/a607c149-6bf6-0fd0-0e31-100378504da2@kernel.dk/ Reported-and-tested-by: Jens Axboe Tested-by: Daniel Scally Cc: Andy Shevchenko Signed-off-by: Linus Torvalds --- include/acpi/acpi_bus.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index b9d434a93632..13d93371790e 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -720,7 +720,8 @@ static inline struct acpi_device *acpi_dev_get(struct acpi_device *adev) static inline void acpi_dev_put(struct acpi_device *adev) { - put_device(&adev->dev); + if (adev) + put_device(&adev->dev); } struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle); -- 2.20.1