Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 12/23] ACPI: fix NULL pointer dereference | Date | Fri, 6 Aug 2021 10:16:44 +0200 |
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From: Linus Torvalds <torvalds@linux-foundation.org>
[ Upstream commit fc68f42aa737dc15e7665a4101d4168aadb8e4c4 ]
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: Sasha Levin <sashal@kernel.org> --- 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 4d67a67964fa..1e5ae3b01eb2 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -681,7 +681,8 @@ acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv); static inline void acpi_dev_put(struct acpi_device *adev) { - put_device(&adev->dev); + if (adev) + put_device(&adev->dev); } #else /* CONFIG_ACPI */ -- 2.30.2
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