| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.13 143/223] ACPI: fix NULL pointer dereference | Date | Mon, 26 Jul 2021 17:38:55 +0200 |
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From: Linus Torvalds <torvalds@linux-foundation.org>
commit fc68f42aa737dc15e7665a4101d4168aadb8e4c4 upstream.
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 <axboe@kernel.dk> Tested-by: Daniel Scally <djrscally@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- include/acpi/acpi_bus.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -711,7 +711,8 @@ static inline struct acpi_device *acpi_d static inline void acpi_dev_put(struct acpi_device *adev) { - put_device(&adev->dev); + if (adev) + put_device(&adev->dev); } #else /* CONFIG_ACPI */
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