| From fc68f42aa737dc15e7665a4101d4168aadb8e4c4 Mon Sep 17 00:00:00 2001 |
| From: Linus Torvalds <torvalds@linux-foundation.org> |
| Date: Sat, 24 Jul 2021 15:25:54 -0700 |
| Subject: ACPI: fix NULL pointer dereference |
| |
| 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 */ |
| |
